R520: 32 PS pipelines? Any truth to this?

Discussion in 'Pre-release GPU Speculation' started by Acert93, Jun 1, 2005.

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  1. Acert93

    Acert93 Artist formerly known as Acert93
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    http://www.xbitlabs.com/news/video/display/20050530100343.html
    I have not followed the new GPUs very closely mainly because there is a lot of smoke and mirrors. I remember before the 6800 and X800 were released there was the bombshell that ATI was going with a 12 PS part, and then it came out that NV may go with a 16 PS part. Then ATI went with a 16 PS part.

    But the rumors for G70 right now are 24 PS at 430MHz at 110nm. It just seems like a huge leap for a 32 PS part at 90nm. Really risky...

    So, is there any truth to either sides rumors? What are people expecting?
     
  2. digitalwanderer

    digitalwanderer Dangerously Mirthful
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    Well the 90nm bit is right, as for pipes I've been burned once too many times before to offer you a prediction. :oops:
     
  3. Acert93

    Acert93 Artist formerly known as Acert93
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    I guess I see these new parts as "refreshes" as long as neither makes a power move. And unless one or the other has figured out how to get a ton more bandwidth or more intelligent use of bandwidth, it seems a 2x increase in PS performance would hit memory limitations. It seems GPUs have scaled, to a degree, with the memory available.

    So that is why I am asking. Are these 32 PS rumors just bunk? These are refreshes after all... the 100% jumps always seem to happen 2 years after a new generation. NV40 / R420 were last year this time so I guess I was expecting big jumps NEXT year, not this year.

    That is why a 32 PS part seems... crazy. But if ATI pulled that off with decent features and a high frequency... wow, just wow.

    But then again, maybe NV is secretly doing the same thing? Both are goot at hiding stuff...
     
  4. Pete

    Pete Moderate Nuisance
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    I'm expecting G70 to be 32 pipes as well, if only b/c we've always seen a doubling of pipes (and also b/c the last gen's rumors also undercounted the pipes). 24-pipe cards may be like today's 12-pipe ones, one rung down from the top.

    But maybe card makes are more comfortable with non-power-of-two pipe setups, especially if they're moving toward more general-purpose shader ALUs.
     
  5. PaulS

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    Ultimately, a lot of things are very unclear right now. I'd be surprised if NVIDIA have kept the 32 pipeline rumour under wraps for this long if it's true, since even the NV40/R420 plans had been fully revealed by this point in proceedings in 2004. Somehow, however, R520 having 32 pipelines seems more believable, if only because of everyone being so quick to count ATi out, and pretend there's some huge behind the scenes problem.

    I don't know, I just sense something is coming. Maybe I'll be proved wrong. I kind of hope so, since I don't especially want these cards to be unmatched.
     
  6. Charmaka

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    El Reg are claiming 24 pipes and they usually pretend to be respectable when making statements of fact.
     
  7. no-X

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    24 pipes for G70 or R520?
     
  8. Charmaka

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  9. Nick

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    Couldn't that be 32 unified pipelines? So most of the time it would act like ~24 pixel pipelines and ~8 vertex pipelines. This seems reasonable on a modern process.

    I'd still be surprised to see ATI immediately use 90 nm though...
     
  10. KimB

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    Well, I've said it before, so I'll say it again:
    I don't think we're yet at the transistor counts to actually make 32 pipeline cards viable (Well, ATI might be able to pull it off with an Xbox2-like memory design, but I seriously doubt that design will make it to the PC, and it'd be expensive as hell anyway).
     
  11. Mark

    Mark aka Ratchet
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    24 pipes seems so unround for nVidia. Smoke and mirrors I expect.
     
  12. KimB

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    But for 32 you'd need to vastly simplify the pipelines to get it to be within the ~300 million transistor count this generation's going for.
     
  13. kemosabe

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    Being discussed in this other thread in the wake of new rumours.
     
  14. Geo

    Geo Mostly Harmless
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    Well, NV has apparently done 24 pipes at 110nm without low-k. So I don't see 32 pipes at 90nm low-k as technically out of the question.

    Which isn't to say that's what they did --but I dont' see any reason to rule it out on technical grounds. I can't entirely dismiss the possibility that the best informed public sources I'm aware of have been fed extreme misinformation.
     
  15. t0y

    t0y
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    The pipelines themselves can be very, very simple and consisting mainly of state. Imagine 32 pipelines only doing actually work in branches/logic/simple OPs and relegating maths to shared general purpose ALUs and texture fetches to dedicated shared units, as well. If this generalising thing actually makes it this generation, I think the division of 32 between 24 pixel and 8 vertex pipelines is a bit strange. The driver may choose wether to make VSs go through the GPU or CPU depending on load but that's about it, assuming all pipes will be running the same code at the same time.

    Of course, this is 100% speculation. :D
     
  16. Unknown Soldier

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    Rumours had it that the R520 would come with 32 pipes but with 8 disabled for a total of 24 pipes. There were other rumours that said the 32 pipe version would be called the R580.

    Go figure.

    US
     
  17. DOGMA1138

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    people missuse the term pixel shader so much that its hard to give straight answer.
    but...
    32 fragment pipelines/pixel "shader" pipelines(64 shader units if there are 2 ALU`s per pipe) - yes
    32 pixel pipeline - porbably not
    no need for so much fill rate(under current core speeds), they will probably cut down on the ROP`s to 24 even bit lower, prehaps 2:1 PS to ROP ratio - 32PS`s 16ROPs.
     
  18. cho

    cho
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    32 TMUs is possible.
     
  19. Hellbinder

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    32/16
    24/12
     
  20. ANova

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    How about 16 pipes (3 ALUs per pipe) :)
     
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