8 ms·

AMD silently removes memory encryption from consumer Ryzen CPUs

454 points by lompad 4mo ago

Integer 4mo ago
I had this enabled as it protects against RAMbleed/ECC errors, so it's not limited to physical attacks.
- riobard 4mo ago
  Are you sure? I thought it's just AES without any authentication.
  - bonzini 4mo ago
    Yes, it's AES with a tweak based on the physical address. It adds some protection from RowHammer and the like because flipping a bit in encrypted memory is catastrophic, while it can be done in a controlled manner if it's not encrypted.
    - Karliss 4mo ago
      Whether you get controlled bit flip depends on exact encryption mode used. Haven't seen any document with enough technical details on how exactly their encryption scheme works. Many of traditional block cypher encryption modes do `cypher_text = plain_text ^ block_chypher_output` with the differences being what goes into block cypher input. This means that single bit flip in cypher text maps 1:1 to bit flip in corresponding decrypted block (and sometimes uncontrolled flips in next block). For malleability prevention full protocols would use MAC in addition to encryption. That's not very practical for memory encryption. Ability to use of various chaining modes is limited since you don't want to re encrypt whole ram when single byte changes or otherwise reduce parallelization of ram processing. Only traditional mode which doesn't degrade parallelization is counter mode, but that's fully susceptible to controlled bit flips. Maybe they can use chaining at cache line or cache block level. This made me think. If the memory controller is already implementing encryption with limited chaining at block level. It wouldn't take much more additional resources to include hardware MAC as well, thus providing much stronger error detection (not correction) capability compared to typical ECC. The fact they aren't advertising it makes me think they aren't doing it, thus using some kind of counter mode variation and thus no extra bitflip protection.
    - IshKebab 4mo ago
      Surely ECC already does that. You don't need encryption.
      - bonzini 4mo ago
        Not that common on consumer hardware.
        iririririr 4mo ago
        well, not NOW
      - undersuit 4mo ago
        ECC just makes it take longer to find the right conditions for Rowhammering. You need to flip more bits in one go to override ECC integrity checks.
  - crest 4mo ago
    Which encrypts each cache line with a key unknown to the attacker. This means an attacker can't target individual bits. Every change affects at least one AES encrypted block. It's much stronger than any normal defence against row hammer in that regard because flipping a single bit in plaintext changes ~half the bits in the ciphertext. It's similar to how Apple uses always on disk encryption instead of the normal means to limit run length in their NAND flash controllers. If the encryption is "off" it just means the decryption key is stored somewhere in the trusted enclave.
hydrogenbon007 4mo ago
crazy amd was the leader for secure memory encryption for consumer while no competitor provided it
lompad 4mo ago
Any idea what's happening? This sounds _bad_.
- ykonstant 4mo ago
  I would also like to know. Surely some people here have at least second-hand knowledge, and silence can sometimes be deafening.
  - porridgeraisin 4mo ago
    It's not bad at all. Long story short, this feature prevented people stealing your ram stick off of your machine, super-freezing it and quickly moving it to their machine before the charge runs out and read off whatever bits are still left intact. It prevented it by having a hardware module on the CPU's memory controller that AES encrypts the contents you are sending to DRAM, and decrypts it before reading it back to the CPUs memory structures. All with hardware keys completely invisible to software (and one that is basically impossible to manipulate physically). And you need to be able to do it multiple times for the bits of memory that you want to snoop on, to be the bits that survive the transfer.
- themafia 4mo ago
  > To be fair to AMD, there is no clear indication that the company ever publicly advertised TSME as a consumer Ryzen feature. A feature that was possibly accidentally enabled on consumer chips is now being disabled. I would guess that the number of owners of consumer chips who also relied on them for encryption is exceedingly small. The primary concern persists. The manufacturer has an exceptional amount of control of the state of your CPU most of which you cannot change and an unknown chunk of which you cannot even see. We are sort of playing in a fools paradise.
  - Ygg2 4mo ago
    To be fair same can't be said of ECC, even though ECC should be basic feature out of the box.
  - 4mo ago
ZiiS 4mo ago
If it can be silently removed was it a security feature? Whilst I hate companies paying engineers to make things worse just to segment their market; I am not really seeing this as an important feature outside the data-center? If an evil-maid has hardware access they hack the USB and/or PCI not the RAM surely?
- mike_hock 4mo ago
  Sneakily and silently removing a feature in a firmware revision is not acceptable, security or otherwise.
  - p0w3n3d 4mo ago
    if anyone does it sneakily, there is alleged wrongdoing attached to it. I can imagine multiple scenarios like some well-known Israeli company "selling their software only to governments", paying quite amount of money for it, because they were unable to break this one.
    - close04 4mo ago
      > there is alleged wrongdoing attached to it Probably not from a legal perspective, but morally yes. Apple cause batterygate with good intentions but sneakily. Not being transparent is what shot them in the foot. AMD didn't learn anything or thinks this is small-time so no blowback (sadly they might be right).
      - zx8080 4mo ago
        > Apple cause batterygate with good intentions but sneakily. Sure, the Apple's intentional performance degradation of older iPhones was caused by only good intentions, not a form of planned obsolescence in any way. How could it be?
        russelg 4mo ago
        If you ever had to use an iPhone that would just shut off randomly with like 30% battery "remaining", you'd probably be singing a different tune and appreciative your device became somewhat more usable with the changes.
rekttrader 4mo ago
Hint: NSA said no.
- NooneAtAll3 4mo ago
  NSA added disabling switch in the first place
- zamadatix 4mo ago
  Why did the NSA wait 9 years to say no & why does that explain the coincidence of the feature being supported in the PRO variants of the same CPU, which just happen to cost more? If the NSA wanted to say no they'd just ask for some kind of back door and call it a day.
- HDBaseT 4mo ago
  AMD PSP probably already works around it anyways.
garganzol 4mo ago
For what it's worth, RAM encryption belongs to professional SKUs. It's the right business decision that should have been made from from the very beginning. For most consumer users, RAM encryption primarily adds power consumption and heat generation while providing little practical benefit. They simply don't face many of the threat vectors and attack scenarios that certain industries and enterprise environments must contend with.
- rubyn00bie 4mo ago
  This is an absurd take since the referenced chips in the article are all desktop parts, and the power usage is dwarfed by any “modern” (within the last five years) GPU. There are many people, myself included who opt to use security features like this. All this does is reduce security for folks without any legitimate reason. “Power consumption” is absolutely not a valid excuse to completely disable it. I’ve been a fan of AMD for a while now but they’re really jumping the shark these days. It’s a real shit situation we’re all in because of the lack of competition in consumer CPUs. I can only hope things like RISCV take off sooner than later.
- baq 4mo ago
  how do you know what threats I face? how do you know what threats journalists and whistleblowers face? this is approximately the same discussion as with ECC RAM: the benefits vastly outweigh the slight performance loss and die area increases.
  - bakugo 4mo ago
    ECC passively benefits everyone, even people who don't know what it is or why it's useful. Anyone can be a victim of random bit flips, it's not a targeted threat. Memory encryption, on the other hand, provides absolutely no benefit to 99.999% of users. If you consider yourself to be such a high value target that you suspect someone might gain physical access to your hardware without your knowledge and carry out extremely sophisticated hardware attacks to extract your data, you are a tiny minority and it makes sense that such niche protections would require buying specialized hardware. Even then, the odds of such an attack being chosen instead of a far less sophisticated software-based approach are also tiny. Of course, if the hardware itself supports the feature and AMD simply decided to disable it, that's still a shitty thing to do, but let's not pretend that it is in any way comparable to ECC.
miga 4mo ago
It is sad that once again we will be exposed to more criminals trying to steal our data. Memory encryption not only allows to secure memory from physical "cold RAM", but also prevents loss of encryption keys as it hides the content during transfer.
thg 4mo ago
This was never marketed as a feature of the consumer CPUs and if some malignant actor does get physical access to my (consumer) hardware, then them being able to read out bytes through cryo-freezing the RAM really isn't high up on the list of things I'm going to worry about.
- close04 4mo ago
  Transparent communication would have been appreciated nonetheless. You have customers not just lawyers on the other side, it's not just about making sure you're legally covered.
  - thg 4mo ago
    Let me give you an analogy: If you e.g. figure out some undocumented endpoints for a REST API, which are intended for internal use only, and started using them, do you expect the developers to inform you about changes? As far as AMD is concerned, this was never supported, nor documented. Now pulling the rug with a firmware update isn't a very nice thing to do, but maybe they've had some actual reason for that beyond "this shouldn't be enabled". Nobody should expect undocumented and unsupported features to just continue to work in perpetuity, simply because they did work at some point in the past.
    - cwillu 4mo ago
      That's an asinine take. We're not talking about a remote subscription service changing an undocumented implementation detail. Physical artifacts shouldn't lose features due to the remote action of the company that made them.
    - kubik369 4mo ago
      There is more nuance to this. Let me give you a better example that actually happens — SSDs. Manufacturer will tell you some miniscule amount of specifications, such as that the drive reads and writes some amount of MB/s. That's basically the only spec you get. Reviewers review this drive. It is a really good drive, dedicated controller, MLC/TLC flash, all the good stuff. It gets raving reviews. Some months after this, during which the drives have been selling like hot-cakes and have been recommended everywhere, the manufacturer swaps parts, without creating a new SKU/model. Some examples are swapping TLC flash for QLC flash, making the SSD DRAMless when it had a dedicated RAM before and such, all negatively affecting the performance in some way. After the changes, you can still read/write with the advertised speeds, but only for 10GB instead of indefinitely or the drive has much worse latency or what have you, you basically got bait-and-switched and bought an inferior product to what was expected. The question is, is this ok? I think it is not ok, even though the manufacturer technically did not promise all the seemingly undocumented stuff (although one could argue that it has been documented by the reviewers).
Elfener 4mo ago
I would be fine with this if it meant CPUs became slightly cheaper, but we know that's not going to happen. And there's been talk that now the so-called "AI companies" will start using more CPUs as well, due to "personal agentic agents", so I hope that people won't be priced out of CPUs too...
shiiiit 4mo ago
This will be re-added in a few years. The current flip-flop is just enshittification.
k__ 4mo ago
I'm curious about Denuvo's opinion on that.
- Retr0id 4mo ago
  Why would Denuvo have an opinion?
- nicman23 4mo ago
  denuvo is dead in the water right now, anyways
- akimbostrawman 4mo ago
  AMD's memory encryption is completely transparent and irrelevant to the OS and its applications hence the transparent in the name.
- 15155 4mo ago
  In a post-LLM world, Denuvo has far greater issues.
- not_a9 4mo ago
  This does not fit DRM/anticheat threat model anyway.
bflesch 4mo ago
It's a shame there is no software-based memory encryption included in the linux kernel. Especially cloud providers can easily snoop all your keys and you have zero recourse.
- benjojo12 4mo ago
  In a cloud provider situation there is no pure software solution to this, the hypervisor can always dump your memory pages / register states
  - bflesch 4mo ago
    It's one piece of a proper defense-in-depth approach. Europe needs to hope for the best but prepare for the worst.
- matja 4mo ago
  There was a patch called Tresor that did this, but I don't think it was updated for a long time. You have to store the encryption key in CPU registers and ensure it's not saved to RAM during task switching or power suspend operations. Tresor used x86-specific debug registers for it, but you could potentially use unused SIMD registers if you masked-off the CPUID bits for them and disabled them for access by user-space. But securing against attacks from a hostile hypervisor or a server provider needs more than just memory encryption, because they can intercept any part of the boot process and control the hardware/firmware that can lie to your kernel. To counter that you'd need something like AMD SEV(ES/SNP) with measured boot and remote attestation to switch the only thing you trust to the CPU manufacturer (best you can do IMO).
  - pbmonster 4mo ago
    > You have to store the encryption key in CPU registers and ensure it's not saved to RAM during task switching or power suspend operations. Interesting insight. Any reason why the key can't be kept exclusively in the secure enclave / trusted platform module / crypto coprocessor?
pjmlp 4mo ago
Another example on how AMD is hardly the good guys.
rusk 4mo ago
I wonder what the additional power draw of these features would be. Parenthetically, I wonder often about the energy impact of all these HTTPS localhost links, and is there a point where defense-in-depth has to give way to other concerns? But yeah 95% of the consumer market don't care about this and it's only adding unnecessary costs
- Karliss 4mo ago
  Consumers were always capable of disabling it themselves if they didn't need it. The performance impact seems to be ~3% on average, impact on power consumption is probably similar or less since any extra delay idling can destroy performance while not having as big impact on power consumption. https://www.phoronix.com/review/amd-memory-guard-ram-encrypt/4 https://www.phoronix.com/review/amd-memory-guard-ram-encrypt... Any extra cost would be mostly due to power consumption and testing that the feature works (which they probably don't do for consumer skews anyway). The area of silicon used by the feature is probably negligible, from the manufacturing cost perspective it's cheaper to avoid any unnecessary design differences between skews.
- undersuit 4mo ago
  Despite it being hardware accelerated I've always wondered what the energy cost for HDCP encryption on HDMI connections is.
pshirshov 4mo ago
To be honest it never worked great - many issues (mostly freezes) with VFIO, NVidia drivers, amdgpu...
crest 4mo ago
AMD is busy learning all the wrong lessons from Intel.
hgoel 4mo ago
It's pretty crazy that we have this entire segment of features that companies artificially restrict from the average person and overinflate the price of, for no real reason. GPU virtualization is another example of such a feature. The market segmentation arguments don't really work either, enterprises are paying the big bucks for more than just these standalone features.
- loloquwowndueo 4mo ago
  Reminds me of subscription heated seats in bmw cars. The hardware is already there, you paid for it and you can’t use it unless you give the automaker a revenue stream on top of the tens of thousands you already paid for the car.
  - blacklion 4mo ago
    Same with some old IBM hardware: two CPUs were installed in each box, but if you bought only 1 CPU server other one is disabled via firmware.
    - OGWhales 4mo ago
      Oh, they still do that with their new hardware. The machine comes with x amount of processor cores, but you can't use any of them without paying. How much you pay depends on the "MSUs" you agreed to, MSU being a proprietary measurement system by IBM. Other software you run is billed relative to your MSU tier. So, if you run z/OS then your cost will be higher if your machine has more MSUs. A weird quirk of this is that there is thing called "IFLs" (Integrated Facility for Linux) which, when I when I first heard of them, I thought was a separate processor designed for for linux. However, it is not. It is actually the same as the regular processors that run z/OS etc, the difference is that is is licensed exclusively for running Linux (or like z/VM to run linux counts too). The reason for this is to enable shops that want to run linux and needed extra horsepower to do so, but didn't want their z/OS bills to go up because they purchased more MSUs. So, despite buying more of the processor capacity within the mainframe, it doesn't count towards the "MSU" number that impacts the cost of various software because you are using with one type of software vs another type of software.
nickdothutton 4mo ago
This sort of shenanigan is why it’s important to have a competitive market for CPUs.
- functionmouse 4mo ago
  it's exactly why we're not allowed a competitive market for CPUs we could all be burning our own tiny ~300nm feature size ICs at home for around the price of a blu ray burner and a dark room setup. Our silicon limitations are not for a lack of hardware, but rather a lack of freedom.
  - bob1029 4mo ago
    > a lack of freedom > ~300nm feature size Can you point to a specific regulation that prevents me from crafting shitty semiconductors in my shed? I am pretty sure there are entire YouTube channels dedicated to this.
    - kouteiheika 4mo ago
      > I am pretty sure there are entire YouTube channels dedicated to this. There is: https://www.youtube.com/@Dr.Semiconductor https://www.youtube.com/@Dr.Semiconductor
    - margalabargala 4mo ago
      IP laws. You personally might be able to do this. But should you attempt to sell a device that makes it easy for anyone to do, you will get sued into oblivion. There's a big difference.
    - fc417fc802 4mo ago
      I think it's less any regulation and more the lack of products to facilitate it. The guys rolling their own from scratch on youtube weren't anywhere near 300 nm last I checked.
      - 15155 4mo ago
nickjj 4mo ago
I don't know how this works but does this mean if someone gained physical access to your locked running computer, they could gain access to your full encrypted drive and anything saved on disk? My reasoning there is if you used an encrypted drive, the decryption key you type when booting up would be stored in memory for the duration of that boot. This seems alarming because it means if someone broke into your living quarters they can bypass all forms of disk encryption if your machine was on and locked. Encrypting your disks seems like a reasonable thing to want to do with consumer grade hardware.
- pshirshov 4mo ago
  This feature was off by default in all the mobos I've seen. It causes many stability issues, as to my experience. The attack is sophisticated, Mr.Nobody, generally, should not worry about expensive cryogenic attacks - three letter guys would extract your key with a wrench. I mean the change is bad - it undermines already damaged trust, but the "average Joe" is extremely unlikely to be affected directly. There are many much cheaper ways to force you to give up your keys.
  - akimbostrawman 4mo ago
    >It causes many stability issues, as to my experience In my experience it very much does not, ram instability with this feature indicates a hardware issue same as with ECC. >Mr.Nobody, generally, should not worry about expensive cryogenic attacks - three letter guys would extract your key with a wrench. This is disingenuous framing. There exist valid threat models for average people between thieves and three letter agencies. Police forces and organized crime have been known to use ram freezing, the former is not known for wrench attacks. That scenario is only good for hand waving real concerns anyways.
    - pshirshov 4mo ago
      Well, I've experimented with this feature on several platforms (both ECC and non-ECC) starting with TRX40, most of the times I've been just getting hard freezes at GPU driver initialization. If it boots - it usually hangs when a VFIO VM spins up.
ciupicri 4mo ago
From yesterday: "Users cry foul after AMD stripped memory crypto from its consumer CPUs", https://arstechnica.com/security/2026/06/users-cry-foul-after-amd-stripped-memory-crypto-from-its-consumer-cpus/ https://arstechnica.com/security/2026/06/users-cry-foul-afte... ( https://news.ycombinator.com/item?id=48559827 https://news.ycombinator.com/item?id=48559827 )
- deleted 4mo ago
  [deleted]
sva_ 4mo ago
So it seems that the Ryzen PRO in my HP EliteBook is not affected.
SirFatty 4mo ago
"silently" Everything is done silently and quietly nowadays.
- Retr0id 4mo ago
  Because they're words LLMs like to use. But in this instance it seems like the word a human would pick, too.
- niam 4mo ago
  "AMD, with nary antecedent aforenotice, has elected to excise"...
- supertrope 4mo ago
  I get your point. I assume the intent is to call out companies on marketing good things and trying to bury customer unfriendly things. As a customer you can assume that if a company is not drawing attention to something, it's not good or at least the feature is not there.
  - SirFatty 4mo ago
    I don't think you got it... it's a lazy way of writing headlines, and as someone else pointed out, it's an AI thing. Search news.google.com for silently or quietly and be amazed how many hits there are.
Anounimus 4mo ago
[flagged]
alberth 4mo ago
Makes sense. The ECC in consumer line is what created an entire market for use in inexpensive web hosting. Then AMD created their EPYC variants, and it wasn’t clear what the difference was between the consumer & Epyc models.
- zamadatix 4mo ago
  No clear difference beyond the scaling to 6x the memory channels, 24x the memory capacity, 12x the core count, 6x the PCIe lanes, and ability to double (or nearly double) these with a 2nd socket. There are also a few features, like per VM memory encryption, which have only ever been on Epyc (and "real" Epyc, not just any Epyc branded consumer platforms). Like the article hits spot on right at the start, it has nothing to do with needing to differentiate Epyc somehow and everything to with differentiating the PRO versions of the consumer CPUs: > was suddenly no longer available on AMD CPUs outside the company's Pro lineup The PRO variants are just the standard consumer CPU sold at a $ premium for enterprise targets. They have remote management firmware enabled, get longer firmware and support lifecycles, FIPS certification, and, now, memory encryption over the consumer branded version of the same CPU.
  - alberth 4mo ago
    What’s the different between these two: Consumer: https://www.amd.com/en/products/processors/desktops/ryzen/9000-series/amd-ryzen-9-9950x3d.html https://www.amd.com/en/products/processors/desktops/ryzen/90... EPYC variant: https://www.amd.com/en/products/processors/server/epyc/4005-series/amd-epyc-4585px.html https://www.amd.com/en/products/processors/server/epyc/4005-...
    - zamadatix 4mo ago
      The Epyc 4585PX falls into the `(and "real" Epyc, not just any Epyc branded consumer platforms)` note. I.e. it is the same CPU as the AMD Ryzen 9 PRO 9965X3D, branded differently because it is certified against "server" branded motherboards instead of "standard" PC motherboards (same socket/chipset though, outside firmware validation the two are swappable). It carries none of the actual Epyc feature sets, just the PRO features, and the feature differences are therefore the same as any other PRO CPU.
ChocolateGod 4mo ago
If my memory serves me correctly, this feature was never marketed by AMD for these CPUs and was unstable. The only mistake AMD potentially made here is not being transparent why it was disabled.
nish__ 4mo ago
If you're this serious about security, you should be manufacturing your own hardware.
- Cider9986 4mo ago
  I wouldn't trust myself to manufacture my own hardware. If you're serious about privsec you should use GrapheneOS.
  - nish__ 4mo ago
    Then learn? Otherwise, you have to trust those that do.
- Crosseye_Jack 4mo ago
  If you're this serious about security, then manufacturing your own hardware isn't good enough, you need to create your own big bang to seed your own planet to source your own helium to be used in the production of your own ICs. But even then? can you really trust the research and information about how to produce those ICs if you have not conducted that research yourself personally?
RandyOrion 4mo ago
The github issue that never made it in this news: https://github.com/AMDESE/AMDSEV/issues/292 https://github.com/AMDESE/AMDSEV/issues/292 Silent enshittification in the name of updates is getting out of hand. There are several evidences that downgrading BIOS/AGESA to below 1.2.7.0 to 1.2.0.3 brought back TSME for their AMD cpus. I downgrade my bios as a price for my blind trust on AMD, and yes TSME is back. You lost my trust AMD. The lesson learned is that if your PC with AMD cpu is stable, don't do any bios upgrade, as AGESA in the bios is adversarial to you, the users of AMD cpu.
- RandyOrion 4mo ago
  To people who silently downvoted this: please explain why you did that, you're doing things like AMD.
dd_xplore 4mo ago
No vendor should be able to do this remotely at all. Irrespective of security vulnerabilities present or not.
hugmynutus 4mo ago
Everyone jumping up about "enshitification". I tried to enable this feature on QEMU and it broke my VMs because the secure memory system was board-line hopelessly broken/non-functional. Did anyone even use this feature? Yes it is dishonest to remove features but from perspective AMD disabled a feature that never worked in the first place. The feature never should've been advertised as enabled.
Artoooooor 4mo ago
How can they not anything to say about it? I demand answers both why they sneakily added it and then why they sneakily removed it. Especially if it was a burgerland government intervention.
helterskelter 4mo ago
Ridiculous because AMD built their reputation off of avoiding BS market segmentation like this. It's ironic that the equivalent Intel model has this feature. This has implications beyond simply securing against physical access attacks, but also protects against rowhammer and its ilk. Between this and their recent botched software update verification I'm getting a little wary of AMD.
teravor 4mo ago
there is a MemoryOverwriteRequestControl efivar which I believe is set on by default in linux (need TPM enabled in bios) which will wipe memory on reboot. should also set the MemoryOverwriteRequestControlLock (MorLock v1/v2) if you don't want it ever changed (on 'clean' reboot MOR is usually unset to facilitate a faster boot). there is still the problem of actually triggering the reboot.
nxy 4mo ago
To the general consumer, it doesn’t matter if they remove it or not. Am I wrong? When was the last time ya’ll used this super duper feature?
LoveMortuus 4mo ago
Do companies ever announce when they remove features and degrade products?
- zamadatix 4mo ago
  Yeah.
omgwtfbyobbq 4mo ago
This, like the fluctuations in ram prices, feels familiar. I wouldn't be surprised if lower hardware prices and weaker demand for everything are more likely to lead to more feature rich products to encourage sales, and higher hardware prices hurting sales volume leads to a natural/expected contraction in feature availability to compensate for lower sales.
waterTanuki 4mo ago
> After some more back-and-forth, Kilpatrick asked bluntly whether the flag being set to FALSE on consumer chips was a silicon-level limitation or a firmware policy decision — since one is permanent and the other is potentially reversible. Limonciello’s reply effectively closed the chapter. “My apologies, but I don’t have any more information to share on this topic,” he wrote. Too many people downplaying this as a simple business decision from AMDs side but the response here is what really makes this a story. Where there's smoke, there's fire.
gck1 4mo ago
It is absolutely astonishing that the only hardware brand that cares about security features in consumer space is Apple. How did we even get here?
deleted 4mo ago
[deleted]
hd4 3mo ago
For anyone getting late to the thread, they're reinstating TSME. They shouldn't have had to reinstate it to begin with, but it's good to see the pressure campaign worked. https://arstechnica.com/security/2026/06/following-user-outcry-amd-reinstates-memory-encryption-in-consumer-cpus/ https://arstechnica.com/security/2026/06/following-user-outc...

454 points by lompad 4mo ago

Integer 4mo ago

I had this enabled as it protects against RAMbleed/ECC errors, so it's not limited to physical attacks.

riobard 4mo ago
Are you sure? I thought it's just AES without any authentication.
- bonzini 4mo ago
  Yes, it's AES with a tweak based on the physical address. It adds some protection from RowHammer and the like because flipping a bit in encrypted memory is catastrophic, while it can be done in a controlled manner if it's not encrypted.
  - Karliss 4mo ago
    Whether you get controlled bit flip depends on exact encryption mode used. Haven't seen any document with enough technical details on how exactly their encryption scheme works. Many of traditional block cypher encryption modes do `cypher_text = plain_text ^ block_chypher_output` with the differences being what goes into block cypher input. This means that single bit flip in cypher text maps 1:1 to bit flip in corresponding decrypted block (and sometimes uncontrolled flips in next block). For malleability prevention full protocols would use MAC in addition to encryption. That's not very practical for memory encryption. Ability to use of various chaining modes is limited since you don't want to re encrypt whole ram when single byte changes or otherwise reduce parallelization of ram processing. Only traditional mode which doesn't degrade parallelization is counter mode, but that's fully susceptible to controlled bit flips. Maybe they can use chaining at cache line or cache block level. This made me think. If the memory controller is already implementing encryption with limited chaining at block level. It wouldn't take much more additional resources to include hardware MAC as well, thus providing much stronger error detection (not correction) capability compared to typical ECC. The fact they aren't advertising it makes me think they aren't doing it, thus using some kind of counter mode variation and thus no extra bitflip protection.
  - IshKebab 4mo ago
    Surely ECC already does that. You don't need encryption.
    - bonzini 4mo ago
      Not that common on consumer hardware.
      - iririririr 4mo ago
        well, not NOW
    - undersuit 4mo ago
      ECC just makes it take longer to find the right conditions for Rowhammering. You need to flip more bits in one go to override ECC integrity checks.
- crest 4mo ago
  Which encrypts each cache line with a key unknown to the attacker. This means an attacker can't target individual bits. Every change affects at least one AES encrypted block. It's much stronger than any normal defence against row hammer in that regard because flipping a single bit in plaintext changes ~half the bits in the ciphertext. It's similar to how Apple uses always on disk encryption instead of the normal means to limit run length in their NAND flash controllers. If the encryption is "off" it just means the decryption key is stored somewhere in the trusted enclave.

hydrogenbon007 4mo ago

crazy amd was the leader for secure memory encryption for consumer while no competitor provided it

lompad 4mo ago

Any idea what's happening? This sounds _bad_.

ykonstant 4mo ago
I would also like to know. Surely some people here have at least second-hand knowledge, and silence can sometimes be deafening.
- porridgeraisin 4mo ago
  It's not bad at all. Long story short, this feature prevented people stealing your ram stick off of your machine, super-freezing it and quickly moving it to their machine before the charge runs out and read off whatever bits are still left intact. It prevented it by having a hardware module on the CPU's memory controller that AES encrypts the contents you are sending to DRAM, and decrypts it before reading it back to the CPUs memory structures. All with hardware keys completely invisible to software (and one that is basically impossible to manipulate physically). And you need to be able to do it multiple times for the bits of memory that you want to snoop on, to be the bits that survive the transfer.
themafia 4mo ago
> To be fair to AMD, there is no clear indication that the company ever publicly advertised TSME as a consumer Ryzen feature. A feature that was possibly accidentally enabled on consumer chips is now being disabled. I would guess that the number of owners of consumer chips who also relied on them for encryption is exceedingly small. The primary concern persists. The manufacturer has an exceptional amount of control of the state of your CPU most of which you cannot change and an unknown chunk of which you cannot even see. We are sort of playing in a fools paradise.
- Ygg2 4mo ago
  To be fair same can't be said of ECC, even though ECC should be basic feature out of the box.
- 4mo ago

ZiiS 4mo ago

If it can be silently removed was it a security feature? Whilst I hate companies paying engineers to make things worse just to segment their market; I am not really seeing this as an important feature outside the data-center? If an evil-maid has hardware access they hack the USB and/or PCI not the RAM surely?

mike_hock 4mo ago
Sneakily and silently removing a feature in a firmware revision is not acceptable, security or otherwise.
- p0w3n3d 4mo ago
  if anyone does it sneakily, there is alleged wrongdoing attached to it. I can imagine multiple scenarios like some well-known Israeli company "selling their software only to governments", paying quite amount of money for it, because they were unable to break this one.
  - close04 4mo ago
    > there is alleged wrongdoing attached to it Probably not from a legal perspective, but morally yes. Apple cause batterygate with good intentions but sneakily. Not being transparent is what shot them in the foot. AMD didn't learn anything or thinks this is small-time so no blowback (sadly they might be right).
    - zx8080 4mo ago
      > Apple cause batterygate with good intentions but sneakily. Sure, the Apple's intentional performance degradation of older iPhones was caused by only good intentions, not a form of planned obsolescence in any way. How could it be?
      - russelg 4mo ago
        If you ever had to use an iPhone that would just shut off randomly with like 30% battery "remaining", you'd probably be singing a different tune and appreciative your device became somewhat more usable with the changes.

rekttrader 4mo ago

Hint: NSA said no.

NooneAtAll3 4mo ago
NSA added disabling switch in the first place
zamadatix 4mo ago
Why did the NSA wait 9 years to say no & why does that explain the coincidence of the feature being supported in the PRO variants of the same CPU, which just happen to cost more? If the NSA wanted to say no they'd just ask for some kind of back door and call it a day.
HDBaseT 4mo ago
AMD PSP probably already works around it anyways.

garganzol 4mo ago

For what it's worth, RAM encryption belongs to professional SKUs. It's the right business decision that should have been made from from the very beginning. For most consumer users, RAM encryption primarily adds power consumption and heat generation while providing little practical benefit. They simply don't face many of the threat vectors and attack scenarios that certain industries and enterprise environments must contend with.

rubyn00bie 4mo ago
This is an absurd take since the referenced chips in the article are all desktop parts, and the power usage is dwarfed by any “modern” (within the last five years) GPU. There are many people, myself included who opt to use security features like this. All this does is reduce security for folks without any legitimate reason. “Power consumption” is absolutely not a valid excuse to completely disable it. I’ve been a fan of AMD for a while now but they’re really jumping the shark these days. It’s a real shit situation we’re all in because of the lack of competition in consumer CPUs. I can only hope things like RISCV take off sooner than later.
baq 4mo ago
how do you know what threats I face? how do you know what threats journalists and whistleblowers face? this is approximately the same discussion as with ECC RAM: the benefits vastly outweigh the slight performance loss and die area increases.
- bakugo 4mo ago
  ECC passively benefits everyone, even people who don't know what it is or why it's useful. Anyone can be a victim of random bit flips, it's not a targeted threat. Memory encryption, on the other hand, provides absolutely no benefit to 99.999% of users. If you consider yourself to be such a high value target that you suspect someone might gain physical access to your hardware without your knowledge and carry out extremely sophisticated hardware attacks to extract your data, you are a tiny minority and it makes sense that such niche protections would require buying specialized hardware. Even then, the odds of such an attack being chosen instead of a far less sophisticated software-based approach are also tiny. Of course, if the hardware itself supports the feature and AMD simply decided to disable it, that's still a shitty thing to do, but let's not pretend that it is in any way comparable to ECC.

miga 4mo ago

It is sad that once again we will be exposed to more criminals trying to steal our data. Memory encryption not only allows to secure memory from physical "cold RAM", but also prevents loss of encryption keys as it hides the content during transfer.

thg 4mo ago

This was never marketed as a feature of the consumer CPUs and if some malignant actor does get physical access to my (consumer) hardware, then them being able to read out bytes through cryo-freezing the RAM really isn't high up on the list of things I'm going to worry about.

close04 4mo ago
Transparent communication would have been appreciated nonetheless. You have customers not just lawyers on the other side, it's not just about making sure you're legally covered.
- thg 4mo ago
  Let me give you an analogy: If you e.g. figure out some undocumented endpoints for a REST API, which are intended for internal use only, and started using them, do you expect the developers to inform you about changes? As far as AMD is concerned, this was never supported, nor documented. Now pulling the rug with a firmware update isn't a very nice thing to do, but maybe they've had some actual reason for that beyond "this shouldn't be enabled". Nobody should expect undocumented and unsupported features to just continue to work in perpetuity, simply because they did work at some point in the past.
  - cwillu 4mo ago
    That's an asinine take. We're not talking about a remote subscription service changing an undocumented implementation detail. Physical artifacts shouldn't lose features due to the remote action of the company that made them.
  - kubik369 4mo ago
    There is more nuance to this. Let me give you a better example that actually happens — SSDs. Manufacturer will tell you some miniscule amount of specifications, such as that the drive reads and writes some amount of MB/s. That's basically the only spec you get. Reviewers review this drive. It is a really good drive, dedicated controller, MLC/TLC flash, all the good stuff. It gets raving reviews. Some months after this, during which the drives have been selling like hot-cakes and have been recommended everywhere, the manufacturer swaps parts, without creating a new SKU/model. Some examples are swapping TLC flash for QLC flash, making the SSD DRAMless when it had a dedicated RAM before and such, all negatively affecting the performance in some way. After the changes, you can still read/write with the advertised speeds, but only for 10GB instead of indefinitely or the drive has much worse latency or what have you, you basically got bait-and-switched and bought an inferior product to what was expected. The question is, is this ok? I think it is not ok, even though the manufacturer technically did not promise all the seemingly undocumented stuff (although one could argue that it has been documented by the reviewers).

Elfener 4mo ago

I would be fine with this if it meant CPUs became slightly cheaper, but we know that's not going to happen. And there's been talk that now the so-called "AI companies" will start using more CPUs as well, due to "personal agentic agents", so I hope that people won't be priced out of CPUs too...

shiiiit 4mo ago

This will be re-added in a few years. The current flip-flop is just enshittification.

k__ 4mo ago

I'm curious about Denuvo's opinion on that.

Retr0id 4mo ago
Why would Denuvo have an opinion?
nicman23 4mo ago
denuvo is dead in the water right now, anyways
akimbostrawman 4mo ago
AMD's memory encryption is completely transparent and irrelevant to the OS and its applications hence the transparent in the name.
15155 4mo ago
In a post-LLM world, Denuvo has far greater issues.
not_a9 4mo ago
This does not fit DRM/anticheat threat model anyway.

bflesch 4mo ago

It's a shame there is no software-based memory encryption included in the linux kernel. Especially cloud providers can easily snoop all your keys and you have zero recourse.

benjojo12 4mo ago
In a cloud provider situation there is no pure software solution to this, the hypervisor can always dump your memory pages / register states
- bflesch 4mo ago
  It's one piece of a proper defense-in-depth approach. Europe needs to hope for the best but prepare for the worst.
matja 4mo ago
There was a patch called Tresor that did this, but I don't think it was updated for a long time. You have to store the encryption key in CPU registers and ensure it's not saved to RAM during task switching or power suspend operations. Tresor used x86-specific debug registers for it, but you could potentially use unused SIMD registers if you masked-off the CPUID bits for them and disabled them for access by user-space. But securing against attacks from a hostile hypervisor or a server provider needs more than just memory encryption, because they can intercept any part of the boot process and control the hardware/firmware that can lie to your kernel. To counter that you'd need something like AMD SEV(ES/SNP) with measured boot and remote attestation to switch the only thing you trust to the CPU manufacturer (best you can do IMO).
- pbmonster 4mo ago
  > You have to store the encryption key in CPU registers and ensure it's not saved to RAM during task switching or power suspend operations. Interesting insight. Any reason why the key can't be kept exclusively in the secure enclave / trusted platform module / crypto coprocessor?

pjmlp 4mo ago

Another example on how AMD is hardly the good guys.

rusk 4mo ago

I wonder what the additional power draw of these features would be. Parenthetically, I wonder often about the energy impact of all these HTTPS localhost links, and is there a point where defense-in-depth has to give way to other concerns? But yeah 95% of the consumer market don't care about this and it's only adding unnecessary costs

Karliss 4mo ago
Consumers were always capable of disabling it themselves if they didn't need it. The performance impact seems to be ~3% on average, impact on power consumption is probably similar or less since any extra delay idling can destroy performance while not having as big impact on power consumption. https://www.phoronix.com/review/amd-memory-guard-ram-encrypt/4 https://www.phoronix.com/review/amd-memory-guard-ram-encrypt... Any extra cost would be mostly due to power consumption and testing that the feature works (which they probably don't do for consumer skews anyway). The area of silicon used by the feature is probably negligible, from the manufacturing cost perspective it's cheaper to avoid any unnecessary design differences between skews.
undersuit 4mo ago
Despite it being hardware accelerated I've always wondered what the energy cost for HDCP encryption on HDMI connections is.

pshirshov 4mo ago

To be honest it never worked great - many issues (mostly freezes) with VFIO, NVidia drivers, amdgpu...

crest 4mo ago

AMD is busy learning all the wrong lessons from Intel.

hgoel 4mo ago

It's pretty crazy that we have this entire segment of features that companies artificially restrict from the average person and overinflate the price of, for no real reason. GPU virtualization is another example of such a feature. The market segmentation arguments don't really work either, enterprises are paying the big bucks for more than just these standalone features.

loloquwowndueo 4mo ago
Reminds me of subscription heated seats in bmw cars. The hardware is already there, you paid for it and you can’t use it unless you give the automaker a revenue stream on top of the tens of thousands you already paid for the car.
- blacklion 4mo ago
  Same with some old IBM hardware: two CPUs were installed in each box, but if you bought only 1 CPU server other one is disabled via firmware.
  - OGWhales 4mo ago
    Oh, they still do that with their new hardware. The machine comes with x amount of processor cores, but you can't use any of them without paying. How much you pay depends on the "MSUs" you agreed to, MSU being a proprietary measurement system by IBM. Other software you run is billed relative to your MSU tier. So, if you run z/OS then your cost will be higher if your machine has more MSUs. A weird quirk of this is that there is thing called "IFLs" (Integrated Facility for Linux) which, when I when I first heard of them, I thought was a separate processor designed for for linux. However, it is not. It is actually the same as the regular processors that run z/OS etc, the difference is that is is licensed exclusively for running Linux (or like z/VM to run linux counts too). The reason for this is to enable shops that want to run linux and needed extra horsepower to do so, but didn't want their z/OS bills to go up because they purchased more MSUs. So, despite buying more of the processor capacity within the mainframe, it doesn't count towards the "MSU" number that impacts the cost of various software because you are using with one type of software vs another type of software.

nickdothutton 4mo ago

This sort of shenanigan is why it’s important to have a competitive market for CPUs.

functionmouse 4mo ago
it's exactly why we're not allowed a competitive market for CPUs we could all be burning our own tiny ~300nm feature size ICs at home for around the price of a blu ray burner and a dark room setup. Our silicon limitations are not for a lack of hardware, but rather a lack of freedom.
- bob1029 4mo ago
  > a lack of freedom > ~300nm feature size Can you point to a specific regulation that prevents me from crafting shitty semiconductors in my shed? I am pretty sure there are entire YouTube channels dedicated to this.
  - kouteiheika 4mo ago
    > I am pretty sure there are entire YouTube channels dedicated to this. There is: https://www.youtube.com/@Dr.Semiconductor https://www.youtube.com/@Dr.Semiconductor
  - margalabargala 4mo ago
    IP laws. You personally might be able to do this. But should you attempt to sell a device that makes it easy for anyone to do, you will get sued into oblivion. There's a big difference.
  - fc417fc802 4mo ago
    I think it's less any regulation and more the lack of products to facilitate it. The guys rolling their own from scratch on youtube weren't anywhere near 300 nm last I checked.
    - 15155 4mo ago

nickjj 4mo ago

I don't know how this works but does this mean if someone gained physical access to your locked running computer, they could gain access to your full encrypted drive and anything saved on disk? My reasoning there is if you used an encrypted drive, the decryption key you type when booting up would be stored in memory for the duration of that boot. This seems alarming because it means if someone broke into your living quarters they can bypass all forms of disk encryption if your machine was on and locked. Encrypting your disks seems like a reasonable thing to want to do with consumer grade hardware.

pshirshov 4mo ago
This feature was off by default in all the mobos I've seen. It causes many stability issues, as to my experience. The attack is sophisticated, Mr.Nobody, generally, should not worry about expensive cryogenic attacks - three letter guys would extract your key with a wrench. I mean the change is bad - it undermines already damaged trust, but the "average Joe" is extremely unlikely to be affected directly. There are many much cheaper ways to force you to give up your keys.
- akimbostrawman 4mo ago
  >It causes many stability issues, as to my experience In my experience it very much does not, ram instability with this feature indicates a hardware issue same as with ECC. >Mr.Nobody, generally, should not worry about expensive cryogenic attacks - three letter guys would extract your key with a wrench. This is disingenuous framing. There exist valid threat models for average people between thieves and three letter agencies. Police forces and organized crime have been known to use ram freezing, the former is not known for wrench attacks. That scenario is only good for hand waving real concerns anyways.
  - pshirshov 4mo ago
    Well, I've experimented with this feature on several platforms (both ECC and non-ECC) starting with TRX40, most of the times I've been just getting hard freezes at GPU driver initialization. If it boots - it usually hangs when a VFIO VM spins up.

ciupicri 4mo ago

From yesterday: "Users cry foul after AMD stripped memory crypto from its consumer CPUs", https://arstechnica.com/security/2026/06/users-cry-foul-after-amd-stripped-memory-crypto-from-its-consumer-cpus/ https://arstechnica.com/security/2026/06/users-cry-foul-afte... ( https://news.ycombinator.com/item?id=48559827 https://news.ycombinator.com/item?id=48559827 )

deleted 4mo ago
[deleted]

sva_ 4mo ago

So it seems that the Ryzen PRO in my HP EliteBook is not affected.

SirFatty 4mo ago

"silently" Everything is done silently and quietly nowadays.

Retr0id 4mo ago
Because they're words LLMs like to use. But in this instance it seems like the word a human would pick, too.
niam 4mo ago
"AMD, with nary antecedent aforenotice, has elected to excise"...
supertrope 4mo ago
I get your point. I assume the intent is to call out companies on marketing good things and trying to bury customer unfriendly things. As a customer you can assume that if a company is not drawing attention to something, it's not good or at least the feature is not there.
- SirFatty 4mo ago
  I don't think you got it... it's a lazy way of writing headlines, and as someone else pointed out, it's an AI thing. Search news.google.com for silently or quietly and be amazed how many hits there are.

Anounimus 4mo ago

[flagged]

alberth 4mo ago

Makes sense. The ECC in consumer line is what created an entire market for use in inexpensive web hosting. Then AMD created their EPYC variants, and it wasn’t clear what the difference was between the consumer & Epyc models.

zamadatix 4mo ago
No clear difference beyond the scaling to 6x the memory channels, 24x the memory capacity, 12x the core count, 6x the PCIe lanes, and ability to double (or nearly double) these with a 2nd socket. There are also a few features, like per VM memory encryption, which have only ever been on Epyc (and "real" Epyc, not just any Epyc branded consumer platforms). Like the article hits spot on right at the start, it has nothing to do with needing to differentiate Epyc somehow and everything to with differentiating the PRO versions of the consumer CPUs: > was suddenly no longer available on AMD CPUs outside the company's Pro lineup The PRO variants are just the standard consumer CPU sold at a $ premium for enterprise targets. They have remote management firmware enabled, get longer firmware and support lifecycles, FIPS certification, and, now, memory encryption over the consumer branded version of the same CPU.
- alberth 4mo ago
  What’s the different between these two: Consumer: https://www.amd.com/en/products/processors/desktops/ryzen/9000-series/amd-ryzen-9-9950x3d.html https://www.amd.com/en/products/processors/desktops/ryzen/90... EPYC variant: https://www.amd.com/en/products/processors/server/epyc/4005-series/amd-epyc-4585px.html https://www.amd.com/en/products/processors/server/epyc/4005-...
  - zamadatix 4mo ago
    The Epyc 4585PX falls into the `(and "real" Epyc, not just any Epyc branded consumer platforms)` note. I.e. it is the same CPU as the AMD Ryzen 9 PRO 9965X3D, branded differently because it is certified against "server" branded motherboards instead of "standard" PC motherboards (same socket/chipset though, outside firmware validation the two are swappable). It carries none of the actual Epyc feature sets, just the PRO features, and the feature differences are therefore the same as any other PRO CPU.

ChocolateGod 4mo ago

If my memory serves me correctly, this feature was never marketed by AMD for these CPUs and was unstable. The only mistake AMD potentially made here is not being transparent why it was disabled.

nish__ 4mo ago

If you're this serious about security, you should be manufacturing your own hardware.

Cider9986 4mo ago
I wouldn't trust myself to manufacture my own hardware. If you're serious about privsec you should use GrapheneOS.
- nish__ 4mo ago
  Then learn? Otherwise, you have to trust those that do.
Crosseye_Jack 4mo ago
If you're this serious about security, then manufacturing your own hardware isn't good enough, you need to create your own big bang to seed your own planet to source your own helium to be used in the production of your own ICs. But even then? can you really trust the research and information about how to produce those ICs if you have not conducted that research yourself personally?

RandyOrion 4mo ago

The github issue that never made it in this news: https://github.com/AMDESE/AMDSEV/issues/292 https://github.com/AMDESE/AMDSEV/issues/292 Silent enshittification in the name of updates is getting out of hand. There are several evidences that downgrading BIOS/AGESA to below 1.2.7.0 to 1.2.0.3 brought back TSME for their AMD cpus. I downgrade my bios as a price for my blind trust on AMD, and yes TSME is back. You lost my trust AMD. The lesson learned is that if your PC with AMD cpu is stable, don't do any bios upgrade, as AGESA in the bios is adversarial to you, the users of AMD cpu.

RandyOrion 4mo ago
To people who silently downvoted this: please explain why you did that, you're doing things like AMD.

dd_xplore 4mo ago

No vendor should be able to do this remotely at all. Irrespective of security vulnerabilities present or not.

hugmynutus 4mo ago

Everyone jumping up about "enshitification". I tried to enable this feature on QEMU and it broke my VMs because the secure memory system was board-line hopelessly broken/non-functional. Did anyone even use this feature? Yes it is dishonest to remove features but from perspective AMD disabled a feature that never worked in the first place. The feature never should've been advertised as enabled.

Artoooooor 4mo ago

How can they not anything to say about it? I demand answers both why they sneakily added it and then why they sneakily removed it. Especially if it was a burgerland government intervention.

helterskelter 4mo ago

Ridiculous because AMD built their reputation off of avoiding BS market segmentation like this. It's ironic that the equivalent Intel model has this feature. This has implications beyond simply securing against physical access attacks, but also protects against rowhammer and its ilk. Between this and their recent botched software update verification I'm getting a little wary of AMD.

teravor 4mo ago

there is a MemoryOverwriteRequestControl efivar which I believe is set on by default in linux (need TPM enabled in bios) which will wipe memory on reboot. should also set the MemoryOverwriteRequestControlLock (MorLock v1/v2) if you don't want it ever changed (on 'clean' reboot MOR is usually unset to facilitate a faster boot). there is still the problem of actually triggering the reboot.

nxy 4mo ago

To the general consumer, it doesn’t matter if they remove it or not. Am I wrong? When was the last time ya’ll used this super duper feature?

LoveMortuus 4mo ago

Do companies ever announce when they remove features and degrade products?

zamadatix 4mo ago
Yeah.

omgwtfbyobbq 4mo ago

This, like the fluctuations in ram prices, feels familiar. I wouldn't be surprised if lower hardware prices and weaker demand for everything are more likely to lead to more feature rich products to encourage sales, and higher hardware prices hurting sales volume leads to a natural/expected contraction in feature availability to compensate for lower sales.

waterTanuki 4mo ago

> After some more back-and-forth, Kilpatrick asked bluntly whether the flag being set to FALSE on consumer chips was a silicon-level limitation or a firmware policy decision — since one is permanent and the other is potentially reversible. Limonciello’s reply effectively closed the chapter. “My apologies, but I don’t have any more information to share on this topic,” he wrote. Too many people downplaying this as a simple business decision from AMDs side but the response here is what really makes this a story. Where there's smoke, there's fire.

gck1 4mo ago

It is absolutely astonishing that the only hardware brand that cares about security features in consumer space is Apple. How did we even get here?

deleted 4mo ago

[deleted]

hd4 3mo ago

For anyone getting late to the thread, they're reinstating TSME. They shouldn't have had to reinstate it to begin with, but it's good to see the pressure campaign worked. https://arstechnica.com/security/2026/06/following-user-outcry-amd-reinstates-memory-encryption-in-consumer-cpus/ https://arstechnica.com/security/2026/06/following-user-outc...