AMD Vega 10, Vega 11, Vega 12 and Vega 20 Rumors and Discussion

Discussion in 'Architecture and Products' started by ToTTenTranz, Sep 20, 2016.

  1. silent_guy

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    It's fair to use adjust GPU die size estimates to compensate for differences in die sizes.

    At launch, a 360mm2 Tahiti performed worse than a 300mm2 GK104, but at least the latter had way better FP64 and a 50% larger memory system. And if it had given AMD any traction in the commercial compute space, that cost would have been justified.

    But for Vega I just don't see it. Area is consumed by the units with the highest multiples: shaders primarily, texture units and ROPs and MCs and caches after that.

    A control or management unit that doesn't manipulate data like HBCC isn't the kind of thing that's going to explain a massive die size difference.

    So you are betting on some unknown feature to explain the difference. I don't think that makes sense, and it surprises me that after more than a decade on this board, you're saying that it's unfair to compare die sizes of GPUs are very similar GP102-FP16-adjusted and Vega.

    If Vega turns out to have a large amount of FP64 after all, you'd have a point.

    If AMD decided to spend 40% more area on a speculative, currently unused feature, and betting that it will start making them boatloads of money soon (enough to justify being a year later than the competition), then they made a huge mistake, IMO.

    But I don't think any of that is true: Vega's pathetic results can best be explained by an obscure architectural mistake or corner case bug that could not be fixed without a full base spin. They had no choice but to release one of their worst performing chips ever.

    I believe future Vegas will return to a performance ratio that's more or less in line with Pascal.
     
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  2. DavidGraham

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    TPU preview, trade blows with the 1080:
    https://www.techpowerup.com/reviews/AMD/Radeon_RX_Vega_Preview/2.html
     
  3. DavidGraham

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    Anand's write up:

    http://www.anandtech.com/show/11680...rx-vega-64-399-rx-vega-56-launching-in-august

    Also interesting:
    http://www.anandtech.com/show/11680...-vega-64-399-rx-vega-56-launching-in-august/3
     
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  4. Anarchist4000

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    VegaNano-810x541.jpg
    So these exist!
     
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  5. DavidGraham

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    Wondering where did most of Vega's transistors go? Just to increase clock speeds!
    http://www.anandtech.com/show/11680...-vega-64-399-rx-vega-56-launching-in-august/3

    GCN is really getting old by now. Time for AMD to keep up with something a whole lot different.
     
  6. 3dilettante

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    From Anandtech's write-up, the largest consumer of Vega's additional 3.9B transistors over Fiji is additional drive logic and pipeline stages to take it to higher clocks versus Fiji. Not sure what pixie dust fell on Polaris to allow it to get so close without them.

    Density-wise, Vega is a little more dense than GP104's ~23M transistors/mm2 at 25, barely more than Polaris at ~24, and denser than Fiji's ~15Mt/mm2 but rather short of doubling the density.

    It doesn't seem like GP104 needed to bloat its transistor budget just to get higher clocks than its predecessor. It doesn't seem like the fundamentals for a higher-performing architecture are there. It takes a lot to get it to higher clocks, while AMD is apparently just about done improving things once it adds just the somewhat higher clocks. Is a lack of killer instinct a hardware flaw?

    I guess my hedging that the rasterizer could have been partially on was wrong, it's off.
     
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  7. McHuj

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    I tend to agree. It just seems so odd that the performance/area or performance/watt is so horrid. Something went seriously wrong and they ran out of time to fix it. Now they're polishing a turd.
     
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  8. eastmen

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  9. BRiT

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    I never said it was unfair. I'm saying you're not comparing Apples to Apples. I don't see how it's possible to accurately estimate how much has to be added for the others to add all the advanced Tier 3 features.
     
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  10. revimack

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    Such a disappointing GPU. ~300W on a die larger than GP102 for 1080-level performance? Ouch.

    The cards are priced competitvely strictly on an FPS basis, but bearing in mind the cost of electricity (and the knock-on effects of high GPU power consumption on system reliability) Vega 64 doesn't make much sense.

    Maybe there's a key IP block on the chip that didn't fab properly? Or maybe they expected much higher clocks in retail silicon?

    There has to have been a huge screwup at some point. There's no way these performance figures would have been thought remotely acceptable in the design stages.
     
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  11. eastmen

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    doesn't seem like a huge power diffrence looking at reviews of the 1080 . Dunno how much money you pay for power though
     
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  12. Anarchist4000

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    That would do it. Significant jump over Polaris (~50% more adjusted for CUs) if I did the math right. P100 is around half of that counting registers and L2.

    AMD did confirm the new DSBR wasn't enabled, so more like a giant IP block that isn't currently doing anything. Just need a better idea where all the SRAM went.
     
    #3152 Anarchist4000, Jul 31, 2017
    Last edited: Jul 31, 2017
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  13. revimack

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    The 1080FE consumes ~170-180W under load. In extreme circumstances, it goes to ~200W.

    That's about 50% greater power draw for similar performance, if we take the 295W TDP at face value for Vega 64.
     
  14. seahawk

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    A 99% percentile performance comparison in DX12/Vulkan only against the 1080 and it is practically a draw... and that as cherry picked manufacturer data? We all know that min-FPS suck in BF1 under DX12 with NV, but DX11 works fine. That is bad, really bad.
     
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  15. BacBeyond

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    They aren't releasing more info yet because its clear drivers are still WIP.

    Power management is still WIP:

    Tile based rasterization is disabled currently:

    http://www.gamersnexus.net/news-pc/3004-rx-vega-64-and-vega-56-power-specs-price

    It's clear that memory bandwidth needs to be address since its 50% higher clocks but less memory bandwidth than Fiji, and the Vega 56 will have even less bandwidth since it runs at 850mhz or something like that. There is no way that won't completely bottleneck it and run even slower than Fury X unless they get the new stuff all working in drivers. Once its no longer held back by memory performance should go up a lot. The current scaling vs Fiji is very poor for the huge core clock increase. In Pro tasks which aren't memory bandwidth heavy it does way better.
     
  16. seahawk

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    Was that not the launch?
     
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  17. eastmen

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    Your putting the 1080FE a bit low there from what i can see its around 200w or more. But anyway i am interested in what the $400 card performs like it has a low power draw and if what anand has said about drivers is true we could see some decent gains still.

    The 1080 series has had a long time for driver updates while this chip is new
     
  18. eastmen

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    I'm assuming they are talking about device avalibilty
     
  19. monstercameron

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    that's the 14th...2 more weeks.
    I am very frustrated with the long drawn out reveal process, it's simply not fun.
     
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  20. yuri

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    "Next-gen" CUs... "Poor Volta"... yea sure.

    This card surely takes the place of the worst marketing bullshit ever. It is just a Netbursted GCN with low b/w.

    Given AMD must have got super low R&D for Vega, they should have marketed it differently. No ridiculous events, teasers-of-teasers, trailers, etc.
     
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