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Inside the Steam Deck's APU
- kmeisthax 3y agoSo what exactly were the Magic Leap cores? They don't look like the GPU or CPU cores...
- spuz 3y agoThe specs of the Magic Leap 2 say "14 core computer vision processing engine (CVIP)" which matches the 14 cores shown in the photos.
- jsnell 3y agoThe original source[0] speculates they're computer vision DSPs, specifically Tensilica Vision DSPs from Cadence. [0] https://www.youtube.com/watch?v=ERm1StY-4uY https://www.youtube.com/watch?v=ERm1StY-4uY
- jsheard 3y agoIt wouldn't be the first time AMD has bundled some Cadence DSP cores into their designs, they used them for TrueAudio back in the day as well.
- dfox 3y agoIntel also integrates Tensillica cores as sound DSP (IIRC into PCH not CPU itself). And NXP has some kind of i.MX part that somewhat closely couples Tensillica DSP core(s) to ARM SoC. So I would say that today probably everybody except TI uses Cadence/Tensillica DSP cores.
- kjs3 3y agoI don't think Analog Devices uses Tensillica, and I think NXP still has things in the 56300 derived line shipping, but Tensillica does seem to have soaked up the lions share of DSP functionality these days.
- dfox 3y agoI meant as an DSP core inside some larger chip, not as free standing DSP. It does not make much sense to design a chip that just contains a Tensillica core and nothing else because you lose all of the customizability and the market for such a thing probably is not big enough to offset the NRE and licensing costs (obviously, with Espressif stuff being the exception, but the RF part in there is pretty significant part of the design).
- kjs3 3y agoThat's a fair clarification. The 56000 had a tiny number of SoC-like build-ins (with a 68000), but I don't think they've been sold in decades.
- Red_Leaves_Flyy 3y agoAnd a follow on question… could they be turned on and used?
- jsheard 3y agoProbably not, these modular bits of silicon are usually tied to eFuses that are blown at the factory to irrevocably disable them in SKUs that aren't supposed to have them. Many years ago it was sometimes possible to re-enable disabled cores by poking the right registers, but manufacturers learned their lesson and now they make sure that silicon stays dead. Besides, even if you could enable these DSP cores you'd be hard pressed to do anything useful with them, I don't believe there's any public documentation or tooling whatsoever for Cadence DSPs.
- fulafel 3y agoHow do eFuses work to ensure it's physically irrevocable?
- fragmede 3y agoeg if the fuse blows the line that powers up that part of the chip, then it simply can't power up after the fuse has been blown and thus is unusable. Going in and fixing that blown trace inside of an IC is beyond the capabilities of almost everyone because decapping a chip renders it inoperable.
- fulafel 3y agoI think decapping doesn't necessarily render the chip inoperable, there's some research around attacking tamper resistant hardware and probing the decapped chips while powered on. But you have to be more careful about it of course. Also do all techniques require decapping? Seems in principle you could navigate by x-ray and fix traces disconnected by electromigration efuses using ion beam/implantation, possibly through the packaging. edit: here's someone talking about running decapped chips. https://electronics.stackexchange.com/a/400899 https://electronics.stackexchange.com/a/400899
- modeless 3y agoFunny that AMD would design a bespoke chip for Magic Leap that sold a tiny number of units, and Valve would ride on their coattails for a game console that undoubtedly sold way more. I wonder how much Magic Leap paid AMD for this design? Guess that explains where some of their billions went.
- gjsman-1000 3y agoOne possible explanation is that Magic Leap may have significantly overestimated how many chips they needed, and wondered if someone might buy excess inventory… or at least, might buy out their contract. Consider the first Magic Leap headset. They thought it would do over 100,000 units. It only did 6,000. https://www.engadget.com/2019-12-06-magic-leap-6000-headsets-sold-report.html https://www.engadget.com/2019-12-06-magic-leap-6000-headsets... I don’t know how the Leap 2 is doing. But in the above example, let’s say AMD wanted a minimum order of 100,000. If you were Magic Leap, you’re running to find a buyer - any buyer. You’re also going to cut the price for your batch as far as necessary to cover for possible increased production costs in the future. Even if you recover just half of your costs, it’s better than being forced to buy chips nobody wants that will quickly go stale.
- exmadscientist 3y agoThinking about modern chips in terms of units and inventory isn't the best way to do it. Cutting-edge logic isn't quite priced like software, but it's close enough: the first unit costs $10m in R&D and NRE (Non-Recurring Expenses, like mask sets and test tooling) and then the second unit costs $1 or so. My guess is that Magic Leap, a company infamous for spending profligately, paid for the NRE on this design, and then didn't buy very many of them or pay for exclusivity on it (or let any exclusivity go). AMD is notorious for shopping around designs they've already got ready to ship (probably related to sibling comment's observations about the console graphics market), and Valve runs lean despite not having to, and so this story adds up quite nicely. There may or may not have been some inventory lying around, but the NRE is usually the real story on these things. (It's also possible that the custom Magic Leap sections of this chip have terrible yield -- actually that wouldn't surprise me at all -- and so these were great candidates for die harvest. Which of course is also the sort of thing AMD loves to sell.)
- fbdab103 3y agoHow do they take those CPU pictures? Are those "delidded"? False color xrays?
- exmadscientist 3y agoVery carefully delidded and then with a nice metallurgical microscope. And then usually with focus stacking.
- formerly_proven 3y agoFritzchen's Fritz uses a normal mirrorless camera and macro lens most of the time for the pictures you see everywhere (he posts them under Creative Commons to Flickr, there's an automated pipeline from there to Wikimedia Commons, which is why virtually every Wikipedia article on a CPU or GPU features at least one of his works). Only the clean head-on die-shots (he also does these) need a metallurgical microscope - those are hard to find and very expensive, they're also highly proprietary optical systems, so accessories and objectives are rare and expensive, too.
- namibj 3y agoAFAIK it's the other side of the die from a "delidded" view. So, they desoldered the die, then etched/ground at it until the surface coating was gone, and just the semiconductor structure remains. Due to the sub-micrometer regular structures, you get interference patterns like these. I.e., the color is "structural".
- pdpi 3y agoAMD has almost completely taken over the console market. The PS2 was a MIPS system and the PS3/Xbox360 were PowerPC, but, for the last ten years, Sony and Microsoft have been all AMD. Intel has been out of the game since the original XBox, and nvidia only has the switch to its name. The Steam Deck-style handhelds (like the ROG Ally and the Lenovo Legion Go) are AMD systems. It’s kind of interesting how they have this hold on gaming outside of conventional PCs, but can’t seem to compete with nvidia on just that one market.
- zitterbewegung 3y agoFrom my understanding AMD holds the console market because its basically lowest price wins so the margins are business that Intel and NVIDIA doesn't really want.
- jsheard 3y agoThey also more or less won the PS4/XB1 generation by default as the only supplier capable of combining a half decent CPU and GPU into a single chip - Intel had good CPUs but terrible GPUs and Nvidia had good GPUs but terrible CPUs. That tide is shifting now with Intel's renewed push into GPUs, and Nvidia getting access to high performance ARM reference designs.
- PlutoIsAPlanet 3y agoIt's also interesting that at one point, Nvidia's chips were going to support both x86 and ARM (see Project Denver), but x86 support was scrapped due to Intel's patents. https://semiaccurate.com/2011/08/05/what-is-project-denver-based-on/ https://semiaccurate.com/2011/08/05/what-is-project-denver-b... Would of been interesting to have had another large x86 player
- jsheard 3y agoLast years Xbox leak revealed that Microsoft was at least considering switching to ARM for the next Xbox generation, though regardless of the CPU architecture they chose they indicated they were sticking with AMD for the GPU. It will be interesting to see how that shakes out, going to ARM would complicate backwards compatibility so they would need a very good reason to move.
- danpalmer 3y agoSounds like Magic Leap "overspent" on a custom chip design and fab, like they overspent on everything else, and ended up with a fraction of the sales they expected. And then Valve "underspent" (although perhaps more of an MVP) by taking an existing good-enough chip, perhaps able to get very good yield out of fab (at a time when fabs were costing a fortune), and found yet another corner to cut on a device that is overall pretty low build quality, to hit an aggressive price point. I love my Steam Deck, and I loved the low price, but the build quality is "good enough" at best. Valve have reversed course with the new generation, having a custom chip now that they've proved out the demand, and I expect the device will improve across the board as they take advantage of higher volumes, and perhaps an ability to price a little higher too. I wouldn't be surprised if Magic Leap also reverse course (or already have done? are they still around?) by moving to much cheaper off the shelf or pre-existing hardware.
- Narishma 3y agoIn other words, Valve pulled a Raspberry Pi.
- danpalmer 3y agoI don't know much about the Raspberry Pi situation. Are they using existing designs? Are they doing things like fabbing extra cores to increase yields? I assume they're on an older process anyway. I don't necessarily feel Raspberry Pis are low quality – they're low spec, but I believe the ones I've had in the past seemed good, although I guess there's less stuff to be low quality (vs Steam Decks having a large amount of not-great plastic, control surfaces that fail in very noticeable ways, etc).
- refulgentis 3y agoNote these chips weren't fabbed with extra cores to increase yields
- Narishma 3y agoLike Valve, they initially repurposed an old SoC that was designed for something else, either set-top boxes or phones, don't remember which. After their success they started doing custom work on the follow-up SoCs.
- calamari4065 3y agoNeat. I wonder if these cores are exposed to thr system in any way and if there's anything interesting you can do with them?
- ekianjo 3y agoNo, they are not, and probably disconnected at the chip level
- rubatuga 3y agoDoes anyone know what the die space in the top right is used for? Somebody mentioned secure enclave as another component but I doubt it needs a lot of die space.
- ApolIllo 3y agoGreat article but i wish they mentioned that the APU wasn't in the AR glasses but in the magic leap's Compute Pack
- ekianjo 3y agoWill do!
- rjzzleep 3y agoThe steamdeck works so well, because Valve spent a LOT of effort fixing AMD, wayland and pipewire issues for their handheld. Some of that then trickles down to other machine other parts don't(like sleep, and audio). For example, they have a proper filter chain for their speakers and microphone. Since recently buying an AMD based laptop I've come to realize how much better Intel's software support, both in Linux AND in windows is. And that patterns moves all across AMD product lines. For example, they pressured all vendors to drop S3, dropped it from Phoenix and went all in with Microsoft's s2idle without any clear way to support it. As a result you have multiple vendors with half working idle implementations, overheating and other bugs. Intel has also vastly surpassed AMD is their ML stack, even though their GPU's are less powerful.
- saidinesh5 3y agoThat's quite interesting to know. Which laptop/AMD cpu did you purchase? I may have to buy a new laptop in the near future. Linux is my default OS. I've been happy with my existing Ryzen 7 3000 series laptop for 5 years or so. I want to know if Intel is doing better these days.
- adastra22 3y agoFramework is very well supported on Linux, and have both Intel and AMD builds. Highly recommended.
- pkaye 3y agoHow is Framework power management in Linux? Does it need lot of tweaking in mainstream distributions/
- adastra22 3y agoNot as good as when running windows (when has there ever been a laptop with linux power management as good as windows?), but better out of the box experience than most laptops I’ve tried.
- 3y ago
- phonon 3y agoInteresting to note that the estimated cost for the APU in the Magic Leap 2 is $136.53.[0] [0] https://electronics360.globalspec.com/article/20179/techinsights-teardown-magic-leap-2-ar-headset https://electronics360.globalspec.com/article/20179/techinsi...
- ddalex 3y agoSo that's roughly the power of a 1995 supercomputer or a medium supercomputer (500th place) in 2007, in the palm of your hand... it's bonkers
- burrish 3y agoWhat kind of course do I need to follow to understand CPU architecture and more like the guy in the article ?
- sylware 3y agoMy custom elf/linux takes very few seconds to boot (not a mainstream and massive elf/linux distro which takes foverever on "normal" hardware). I don't even compile sleep/hibertnate stuff. If ever I become super messy, I'll use vim session management in the worst case scenario... :)
- donkeybeer 3y agoIs it running as a general desktop os or is it for some specialized embedded device?
- sylware 3y agodesktop.
- sylware 3y agoACO, the AMD GPU shader compiler from valve (unfortunately in c++ instead of plain and simple C), is full of hardware quirk mitigations. I remember having a look at the documentation about all those quirks (was a text file in mesa at the time)... and I did postpone my alternative to ACO spir-v to AMD GPU ISA translater... ahem (whishing the hardware to go thru some fixing first...).