back to article AMD teases '3D V-Cache' tech that stacks cores and SRAM, delivers 15% boost to today's Ryzen CPUs

AMD has revealed a new 3D die stacking technology it claims delivers the equivalent performance boost to a new generation of processor architecture. The packaging technique was revealed in a keynote address to the virtual Computex exhibition delivered by AMD president and CEO Dr Lisa Su, who said the technology bonds “64MB of …

  1. Gene Cash Silver badge

    Side attacks?

    So does this mitigate any of the side attacks out there? I'm guessing no.

    1. Peter2 Silver badge

      Re: Side attacks?

      Spectre & Meltdown never worked properly on AMD chips and there are no exploits circulating in the wild beyond AMD's documentation example of how a new feature could be abused to perform an attack, which comes alongside detection & prevention methods and a method to disable the feature if desired. Any software protections for Spectre also prevent it.

      https://www.amd.com/system/files/documents/security-analysis-predictive-store-forwarding.pdf

  2. Binraider Bronze badge

    Looking past the marketing spiel - where is Intel on this? The idea of 3d stacking lattices and RAM has been knocking about several years now. Provided the chip yield works out this is amazing. As far as I can tell yield is the only remaining advantage of Intel's older processes.

    Mildly annoying it's a CPU socket change in the next model rather than fitting older boards (yay, more e-waste) though to be fair, we all knew the 3000/5000 were going to share a socket with the one after on a new board.

    1. Boothy Silver badge

      Which socket change? From what I've seen elsewhere, the 3D V-Cache demoed was on a custom 5900X chip, with one chiplet/CCX replaced by one with the 3D V-Cache. So that's Zen 3 on AM4.

      AMD also announced that these 3D V-Cache chips will be available before the end of this year, whereas the new Zen 4 architecture (which will need a new socket) isn't coming out till 2H 2022. So it looks like these new 3D V-Cache will be out well before Zen 4 appears.

      As far as I know, the AM4 to AM5 socket change is due to the switch to DDR5 in Zen 4, so if 3D V-Cache chips come out before Zen 4 does, then that means Zen 3, which still needs AM4 for DDR4.

      At the moment, this is looking like an unexpected and likely final upgrade path for AM4 users, before the move to Zen 4 and AM5 mid 2022.

      1. iron Silver badge

        It could be a nice little boost for my current system and get me a couple of extra years before I need to go for the full rebuild. With luck by then I might even be able to buy a current gen graphics card to go in it.

        1. Boothy Silver badge

          I'm thinking along the same lines.

          I've got a 3800X at the moment, so Zen 2 and 8/12 core/thread.

          The Zen 3 parts are a little faster, but not a massive jump at least not for my use case, which is mostly gaming on that PC (I work on client provided laptops). GPU tends to be the bottleneck for most games.

          My plan is to leave it for a while, at least till Zen 4 has been out a bit, then basically buy whatever the then fastest AM4 part is, assuming my BIOS support it of course.

          Should keep me going for a while without needing a full rebuild, and AM5 is going to need at least DDR5 memory, as well as a new motherboard and CPU, and you can bet none of those will be cheap even a year from now!

    2. Yet Another Anonymous coward Silver badge

      re: Looking past the marketing spiel - where is Intel on this?

      Intel's new CEO have announced that their new share buy-back scheme will be implemented under a new Rule 483 Part B clause which reduces tax-withholding in off-shore accounts by 15 bpp !

      This was made possible by replacing all their semiconductor engineers with world class MBAs

    3. HildyJ Silver badge
      Boffin

      Intel's Lakefield chips are the first to incorporate their 3D stacking technology (Foveros). It's currently available in the Lenovo ThinkPad X1 Fold and the Samsung Galaxy Book S.

      https://newsroom.intel.com/news/up-close-lakefield-intels-chip-award-winning-foveros-3d-tech/

  3. Fenton

    DDR5

    This will be interesting, so much cache + DDR 5 will make these chips a real memory throughput monster.

    They probably don't even need to change much on the Zen architecture as it was always rather memory starved.

  4. Nick Ryan Silver badge

    Picture

    Is it me, or does the picture of the chip that is being held just look like it's three dies put into a single unit rather than anything stacked?

    1. Anonymous Coward
      Anonymous Coward

      Re: Picture

      AMD have already been using multiple "chiplets" in the package rather than a single die - I think two of the chiplets are "compute complexes" and the 3-d stacking is placing SRAM on top of these. By having chiplets they can mix'n'match chiplets that have yielded different numbers of working processor cores for the different products ... also it means that I think that there's a "lucky dip" in some lower end ranges as to whether your chip has all its processor on the same chiplet or spread across both as this has a minor effect on performance.

    2. MCPicoli

      Re: Picture

      The chip at the upper left corner seems to be the one with something (SRAM) stuck over it.

    3. iron Silver badge

      Re: Picture

      That is the other parts of the chip. AMD use a chiplet architecture.

    4. Boothy Silver badge

      Re: Picture

      Other people have mentioned it's chiplets, AMD have been doing this for a couple of generations now.

      The example pictured, is a de-lidded and modified Ryzen 5900X.

      The large silicon at the bottom is the IO die (manages things like RAM, PCIe etc).

      The smaller ones at the top are the CPU dies, in Zen 3, as used here, these can have up to 8 cores each.

      The lower end parts, like the 5600 have a single CPU chiplet, a single 6 core part for the 5600(X) , with the 5800(X) having a single 8 core chiplet.

      In the 5900X and 5950X have 2 chiplets, 6 cores or 8 cores each, so 12 or 16 cores total respectively.

      The top left chip in the pic is the modified Zen 3 core, with the cache added.

      1. Nick Ryan Silver badge

        Re: Picture

        Thanks, that makes a lot sense.

  5. teknopaul Silver badge
    Coat

    rDNA in yer arm

    AMD injecting rDNA in your arm is direct completion to Bill Gates monopoly.

    It's about time we had some competition.

    Each chip comes with a copper and moon perl antistatic intraconnect, to ward off Fivgees.

    1. Yet Another Anonymous coward Silver badge

      Re: rDNA in yer arm

      No you have it wrong, it's intel that goes inside.

      You wear a bracelet of copper AMD chips to ward off pixies and cure rheumatism

      The righteous armor of Nvidia graphics cards is traditionally worn by paladins to deflect girlfriends

      1. ortunk
        Mushroom

        Re: rDNA in yer arm

        "The righteous armor of Nvidia graphics cards is traditionally worn by paladins to deflect girlfriends"

        that drew a laughter and puzzled looks from bystanders

  6. Snake Silver badge

    Heat?

    Still no discussion regarding possible heat-induced RAM errors from the stack, especially since they are pushing this towards gaming whose users are more apt to push the limits - overclock - versus other users. If there is no immediate heat issues, what will the constant heat cycles due to SRAM over many years of ownership? What happens to single-bit circuit failures?

    1. Fenton

      Re: Heat?

      Should not be an issue, Cache does not get that hot. They are stacking the SRAM on top of the cache rather than the logic chips.

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