6 ms·

Microsoft backports AMD branch prediction improvement to Windows 11 23H2

41 points by mariuz 2y ago

lousken 2y ago
i am curious about ryzen 9000 performance on windows 10 but nobody seems to be testing that for some reason
- delfinom 2y ago
  Windows 10 is EOL next year. The world is moving on.
  - archerx 2y ago
    Right off a cliff. I refuse to downgrade to windows 11 and when push comes to shove I will be using Linux, I already use it a lot for my projects so ditching windows won’t be hard at all.
    - SketchySeaBeast 2y ago
      Well, there's no time like the present. What's stopping you from switching right now? If I didn't want to not have to fuss around with games I'd have already made the switch myself.
      - archerx 2y ago
        Inertia and I have some very Windows specific programs that I’m using for my current project and using the alternatives will just be slower. I’m using windows LTSM so I’m good for another few years.
    - jonhohle 2y ago
      That is the analogy unlike to use when people are blinded by “progress”. Sometimes you need to turn around or step on the breaks. I have no issues with Linux for productivity, but gaming is still an issue. :-/
      - keyringlight 2y ago
        I really wonder if this is cueing up another situation similar to what happened with winxp, and wannacry on the many machines still using it years after support ended. There will be some that move over to win11 with varying degrees of enthusiasm or reluctance, but win10 is going to linger. With gaming on linux, there's been a "it just works" attitude with enthusiasts for years but that rings hollow to me in a similar way that "it's just like lego" is for self-building your own PC - it ignores the small mountain of paper cut issues and gotchas it's almost inevitable someone will run into especially if you try to do something off the beaten path. Not all of gaming is neatly within the steam short-walled garden or well-behaved even on windows. It's fine if you have the attitude and time to be prepared to tackle those issues, but nowhere near where I'd want to recommend it for even a small proportion of the tens of millions of PC gamers still using win10.
    - dspillett 2y ago
      Same. My main laptop came with 11 and won't regrade. My desktop at home and “spare” laptop (the one that goes with me where it might get (more) damaged or lost, so I don't want to take the newer/expensive one) are both still running 11. Laptop2 keeps nagging me to “upgrade” but the desktop isn't even compatible (wrong sort of TPM?). They'll be getting the Linux treatment next year, as might the one that is currently on 11. Though I suspect the life will get extended, like happened to XP when small-factor low-spec laptops (and to a lesser extent tablets, though few of those ran Windows or pure Linux, usually Android instead) were popular, there was no way Vista would run on them, and 8 wasn't ready enough for release. With the number of Win10 installs out there that might move to Linux, or be binned and replaced by an Apple device, it might not make sense for them to allow it to EOL without a sudden uptick in Win11 adoption. They'll need to keep supporting 10 for some large commercial and government clients anyway.
    - croutonwagon 2y ago
      Im not so opposed to W11. From a privacy standpoint, W10 has seen most of the crap backported already so its a bit of a wash. Windows 11 is a bit different and does have some wonk still. But there are things integrated that are nice. I moved to an ultrawide recently and the W11 native options for things like window sizing or taskbar management are much better and don't need 3p apps like you do on w10 with the likes of PowerToys or Taskbarx. I still use Linux day to day and may even move there for work to be honest now that I don't do a lot of IC work in windows now.
  - reginald78 2y ago
    I'll have you know my pirated Windows 10 LSTC Enterprise for Internet connected Japanese e-toilets is supported until 2032.
    - antisthenes 2y ago
      As long as my Japanese e-toilet can run Doom, we're good to go.
    - Dalewyn 2y ago
      >Japanese e-toilets The scientific name for them is Toto.
  - lousken 2y ago
    except it didn't? most people are still on windows 10
deng 2y ago
Quite unbelievable how AMD has botched the Zen5 release, especially since there was no need in rushing these CPUs out the door at all. Why couldn't they wait until these improvements were commonly available? Also, at least from initial testing, it seems that these changes improve Zen4 performance almost the same way as Zen5, so at least when it comes to gaming performance, there's currently no reason to expect that Zen5 will be able to justify its increased price tag. I can safely say that buying a 5800X3D was one of the best purchases I ever made, I still see no reason to upgrade...
- Rinzler89 2y ago
  It's not unbelievable when you know AMD's drivers have always been hit or miss since the ATI days, with more misses than hits. Fans call their driver development "fine wine" since they keep getting better over time, while realists call it "not being able to release good drivers from the start, unlike the competition, needing months to reach parity". Yeah, their HW is good, but that's nothing without good SW and AMD still has loads of room for improvement there.
  - Dalewyn 2y ago
    AMD being absolute crap on the software front is where Nvidia simply dominates and Intel still makes for a reasonable purchase.
    - Rinzler89 2y ago
      I have a laptop with AMD and NPU. AMD still has no good easy to use out of the box examples on how to use that NPU for on-device AI applications. Nvidia has been delivering that for over 10 years now. SW seems like an afterthought at AMD. If AMD expects their chips to take off for AI, they should be spamming us with ready made apps and code samples that just work and that we can then modify.
    - puzzlingcaptcha 2y ago
      Much like AMD/ATI, Intel has had botched 3d graphics drivers since at least GMA 900 (probably earlier but that's as far as I remember). Try the new Intel Arc card and see how it works for you.
bhouston 2y ago
Did Intel's stock drop as a result of these AMD performance improvements? Honestly, they are huge improvements and really put the nail in Intel, now it has an even higher road to climb to get competitive again.
- ActionHank 2y ago
  But Intel CPUs are more human than ever, just the other day I read they are killing themselves due to being overworked.
ynik 2y ago
Does anyone know what the technical change in this patch is? I think of branch prediction as being something the CPU does internally; where does the operating system come into play?
- VyseofArcadia 2y ago
  If you have a hot path with a lot of branch mispredictions that can impact performance. Could be as simple as Microsoft found a dumb if inside a tight loop.
- cesarb 2y ago
  I still haven't seen anywhere reporting what, exactly, was the issue, and why would using the "true Administrator" account on Windows (or using Linux) avoid the issue. My own uninformed guess, given that the "true Administrator" account avoids it, would be some sort of security mitigation, for instance flushing the branch predictor state when entering or exiting the kernel unless the current user is SYSTEM or Administrator.
fulafel 2y ago
This doesn't make a lot of sense off the bat, are there more details to the story that explain how CPU branch prediction performance depends on Windows behaviour somehow?
- pixl97 2y ago
  Linux has different performance schedulers you can choose that can dramatically change performance dependant on workloads. It's very possible the CPU is being too smart for its own good and the way Windows is lining stuff up it's not executing branches or something like that. This is just shooting from the hip, but there is a ton of different stuff going on in both the OS and the CPU around this.
  - deleted 2y ago
    [deleted]
- jsheard 2y ago
  The mitigations for Spectre/Meltdown involved deliberately breaking branch prediction across the user/kernel boundary, so it may be as simple as them disabling some mitigations which turned out to not be needed anymore on newer CPU architectures.
- EricE 2y ago
  Dave of Dave's Garage explained it here: https://www.youtube.com/watch?v=OBn3FbKusZI https://www.youtube.com/watch?v=OBn3FbKusZI Basically (according to him) they disabled the spectre/meltdown mitigation if you were an admin - because you were an admin and have full rights to the machine anyway. So now they are doing that for all users? He wasn't clear - or at least it wasn't clear to me. So the mitigations are no longer needed? I think I have more questions than before after listening to that.
  - TiredOfLife 2y ago
    Dave lies. A lot. I would take anything he says with a bucket of salt.
techwiz137 2y ago
In what update is this packaged for Windows 10 and Ryzen 7800x3d?

41 points by mariuz 2y ago

lousken 2y ago

i am curious about ryzen 9000 performance on windows 10 but nobody seems to be testing that for some reason

delfinom 2y ago
Windows 10 is EOL next year. The world is moving on.
- archerx 2y ago
  Right off a cliff. I refuse to downgrade to windows 11 and when push comes to shove I will be using Linux, I already use it a lot for my projects so ditching windows won’t be hard at all.
  - SketchySeaBeast 2y ago
    Well, there's no time like the present. What's stopping you from switching right now? If I didn't want to not have to fuss around with games I'd have already made the switch myself.
    - archerx 2y ago
      Inertia and I have some very Windows specific programs that I’m using for my current project and using the alternatives will just be slower. I’m using windows LTSM so I’m good for another few years.
  - jonhohle 2y ago
    That is the analogy unlike to use when people are blinded by “progress”. Sometimes you need to turn around or step on the breaks. I have no issues with Linux for productivity, but gaming is still an issue. :-/
    - keyringlight 2y ago
      I really wonder if this is cueing up another situation similar to what happened with winxp, and wannacry on the many machines still using it years after support ended. There will be some that move over to win11 with varying degrees of enthusiasm or reluctance, but win10 is going to linger. With gaming on linux, there's been a "it just works" attitude with enthusiasts for years but that rings hollow to me in a similar way that "it's just like lego" is for self-building your own PC - it ignores the small mountain of paper cut issues and gotchas it's almost inevitable someone will run into especially if you try to do something off the beaten path. Not all of gaming is neatly within the steam short-walled garden or well-behaved even on windows. It's fine if you have the attitude and time to be prepared to tackle those issues, but nowhere near where I'd want to recommend it for even a small proportion of the tens of millions of PC gamers still using win10.
  - dspillett 2y ago
    Same. My main laptop came with 11 and won't regrade. My desktop at home and “spare” laptop (the one that goes with me where it might get (more) damaged or lost, so I don't want to take the newer/expensive one) are both still running 11. Laptop2 keeps nagging me to “upgrade” but the desktop isn't even compatible (wrong sort of TPM?). They'll be getting the Linux treatment next year, as might the one that is currently on 11. Though I suspect the life will get extended, like happened to XP when small-factor low-spec laptops (and to a lesser extent tablets, though few of those ran Windows or pure Linux, usually Android instead) were popular, there was no way Vista would run on them, and 8 wasn't ready enough for release. With the number of Win10 installs out there that might move to Linux, or be binned and replaced by an Apple device, it might not make sense for them to allow it to EOL without a sudden uptick in Win11 adoption. They'll need to keep supporting 10 for some large commercial and government clients anyway.
  - croutonwagon 2y ago
    Im not so opposed to W11. From a privacy standpoint, W10 has seen most of the crap backported already so its a bit of a wash. Windows 11 is a bit different and does have some wonk still. But there are things integrated that are nice. I moved to an ultrawide recently and the W11 native options for things like window sizing or taskbar management are much better and don't need 3p apps like you do on w10 with the likes of PowerToys or Taskbarx. I still use Linux day to day and may even move there for work to be honest now that I don't do a lot of IC work in windows now.
- reginald78 2y ago
  I'll have you know my pirated Windows 10 LSTC Enterprise for Internet connected Japanese e-toilets is supported until 2032.
  - antisthenes 2y ago
    As long as my Japanese e-toilet can run Doom, we're good to go.
  - Dalewyn 2y ago
    >Japanese e-toilets The scientific name for them is Toto.
- lousken 2y ago
  except it didn't? most people are still on windows 10

deng 2y ago

Quite unbelievable how AMD has botched the Zen5 release, especially since there was no need in rushing these CPUs out the door at all. Why couldn't they wait until these improvements were commonly available? Also, at least from initial testing, it seems that these changes improve Zen4 performance almost the same way as Zen5, so at least when it comes to gaming performance, there's currently no reason to expect that Zen5 will be able to justify its increased price tag. I can safely say that buying a 5800X3D was one of the best purchases I ever made, I still see no reason to upgrade...

Rinzler89 2y ago
It's not unbelievable when you know AMD's drivers have always been hit or miss since the ATI days, with more misses than hits. Fans call their driver development "fine wine" since they keep getting better over time, while realists call it "not being able to release good drivers from the start, unlike the competition, needing months to reach parity". Yeah, their HW is good, but that's nothing without good SW and AMD still has loads of room for improvement there.
- Dalewyn 2y ago
  AMD being absolute crap on the software front is where Nvidia simply dominates and Intel still makes for a reasonable purchase.
  - Rinzler89 2y ago
    I have a laptop with AMD and NPU. AMD still has no good easy to use out of the box examples on how to use that NPU for on-device AI applications. Nvidia has been delivering that for over 10 years now. SW seems like an afterthought at AMD. If AMD expects their chips to take off for AI, they should be spamming us with ready made apps and code samples that just work and that we can then modify.
  - puzzlingcaptcha 2y ago
    Much like AMD/ATI, Intel has had botched 3d graphics drivers since at least GMA 900 (probably earlier but that's as far as I remember). Try the new Intel Arc card and see how it works for you.

bhouston 2y ago

Did Intel's stock drop as a result of these AMD performance improvements? Honestly, they are huge improvements and really put the nail in Intel, now it has an even higher road to climb to get competitive again.

ActionHank 2y ago
But Intel CPUs are more human than ever, just the other day I read they are killing themselves due to being overworked.

ynik 2y ago

Does anyone know what the technical change in this patch is? I think of branch prediction as being something the CPU does internally; where does the operating system come into play?

VyseofArcadia 2y ago
If you have a hot path with a lot of branch mispredictions that can impact performance. Could be as simple as Microsoft found a dumb if inside a tight loop.
cesarb 2y ago
I still haven't seen anywhere reporting what, exactly, was the issue, and why would using the "true Administrator" account on Windows (or using Linux) avoid the issue. My own uninformed guess, given that the "true Administrator" account avoids it, would be some sort of security mitigation, for instance flushing the branch predictor state when entering or exiting the kernel unless the current user is SYSTEM or Administrator.

fulafel 2y ago

This doesn't make a lot of sense off the bat, are there more details to the story that explain how CPU branch prediction performance depends on Windows behaviour somehow?

pixl97 2y ago
Linux has different performance schedulers you can choose that can dramatically change performance dependant on workloads. It's very possible the CPU is being too smart for its own good and the way Windows is lining stuff up it's not executing branches or something like that. This is just shooting from the hip, but there is a ton of different stuff going on in both the OS and the CPU around this.
- deleted 2y ago
  [deleted]
jsheard 2y ago
The mitigations for Spectre/Meltdown involved deliberately breaking branch prediction across the user/kernel boundary, so it may be as simple as them disabling some mitigations which turned out to not be needed anymore on newer CPU architectures.
EricE 2y ago
Dave of Dave's Garage explained it here: https://www.youtube.com/watch?v=OBn3FbKusZI https://www.youtube.com/watch?v=OBn3FbKusZI Basically (according to him) they disabled the spectre/meltdown mitigation if you were an admin - because you were an admin and have full rights to the machine anyway. So now they are doing that for all users? He wasn't clear - or at least it wasn't clear to me. So the mitigations are no longer needed? I think I have more questions than before after listening to that.
- TiredOfLife 2y ago
  Dave lies. A lot. I would take anything he says with a bucket of salt.

techwiz137 2y ago

In what update is this packaged for Windows 10 and Ryzen 7800x3d?