Nvidia GT300 core: Speculation

Discussion in 'Architecture and Products' started by Shtal, Jul 20, 2008.

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  1. nAo

    nAo Nutella Nutellae
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    I am curious, can you make some practical examples?
     
  2. Jawed

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    In the recent interview,

    http://www.guru3d.com/article/interview-with-ati-dave-baumann/2

    With memory bandwidth in a new spiral thanks to GDDR5 it seems inter-GPU bandwidth is bound to continue being "useless" for quite a while. At least in AMD's eyes.

    Jawed
     
  3. MfA

    MfA
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    Something like COMA has minimal overhead, but there is no symmetry since there is an owner of the data. Keeping things symmetrical has major overhead.

    Show me a SMP supercomputer to prove me wrong ...
     
  4. AnarchX

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  5. suryad

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  6. aaronspink

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    memory order model
    security
    RAS

    Coherency models are at this point well understood with a large backing of both advanced validation and formal models.
     
  7. fehu

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  8. aaronspink

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    Even E/M only hardware coherency has advantages over software only coherency.

    Columbia at NASA AMES
    ASC Purple
    Etc.

    the vast majority of the top 500 list contains SMPs of various scales. Some large, some small.
     
    #768 aaronspink, Apr 22, 2009
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  9. aaronspink

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  10. bowman

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  11. TimothyFarrar

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    Anyone got a translation to this line, "This is not the only change - cluster organization is no longer static. The Scratch Cache is much more granular and allows for larger interactivity between the cores inside the cluster. "

    Sounds to me like "Scratch Cache" is CUDA's "Shared Memory", and that they do dynamic warp formation based on not only branching but also to reduce shared memory bank conflicts (ie the "much more granular")... meaning that you can mostly code without thinking about bank conflicts.

    Going to have to agree with Aaron here that the word "core" is awful in confusing reporters...
     
  12. MfA

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    Directory based ccNUMA.
    64 processor SMP is certainly impressive ... but I wouldn't call it a supercomputer just yet, above that it's "just" a cluster AFAICS.
     
  13. MfA

    MfA
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    Perhaps they carve it up into 4 wide sets, with a crossbar for each set so you can perform single cycle swizzles? (Which would also allow multiple broadcasts within such sets, which would normally cause conflicts.)
     
    #773 MfA, Apr 23, 2009
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  14. aaronspink

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    AKA SMP

    Um, ACS Purple is certainly a super computer. Generally, most supers will involve some level of message passing as there isn't enough of a market in general for very large scale SMPs, as outside of the SC market there is little requirement for that scale of computation.
     
    #774 aaronspink, Apr 23, 2009
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  15. trinibwoy

    trinibwoy Meh
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  16. Crossbar

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    http://forum.beyond3d.com/showpost.php?p=1209408&postcount=980
     
  17. Ailuros

    Ailuros Epsilon plus three
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    Assuming any of it should be true (which for some I have severe doubts) and since I recall your definitions debacle (not entirely unjustified) you could call such a hypothetical chip as either 16 or 32-core depending on definition.


    It might be just one letter difference between SIMD and MIMD, but there's a quite some difference between those two in many aspects. Of course could you call something like a highly optimized SIMD unit eventually MPMD or MPMT, yet it's still no MIMD unit.
     
  18. DegustatoR

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    What you're basically saying is this: "why earn $300 when you can earn $100". Do you really want to say something like this? Because that's clearly b.s.

    Bolded part isn't true at all. I know this for sure. So all the other parts of this phrase are wrong also.

    Doing more with less resources is uninteresting? Doing things that are impossible on AFR system is uninteresting? That's certainly an interesting point of view. Maybe we should go back to Voodoo days since all that flexibility and programmabililty is uninteresting?

    Nothing is tricky in the inefficiencies of AFR. The tricky part is when you try to avoid them. And for that you often loose that flexibility.

    Power/performance is one way to define it.

    However these servers don't use middle class CPUs to achieve that and they certainly aren't selling in mainstream market. Why? If anything we're seeing the opposit process with CPUs: more cores are getting integrated into one big chip. Have you ever thought about this?

    Dual chips will always have some logic that isn't needed in dual chip configuration and that means that their efficiency will always be less than the efficiency of single chip. Single chip will always have some algorythms where it will beat dual chips because of the limitations of AFR mGPU scheme.

    So you've saved some bucks on the die and you've wasted nearly 2x bucks on the price of the card. Are you in the green after that? What if you've missed the sweet spot and even one GPU competitor's card is faster than your mGPU card? If you have some GPU faster than you're using in your mGPU card you may be able to use it in the new mGPU card (GTX295 is an example although not the best one), if not -- you're truly fucked.
    AMD is leaving it's high end dangerously open for a possibility like that. Let's say that LRB will be fast and will use 32nm way ahead of NVs and AMDs GPUs. That could mean that AMD won't have _any_ answer to LRB in the high end _at all_. NV might be able to create some mGPU solution using two big dies, but AMD simply won't have any to make any solution.
    It's a question of having full line up. AMDs line up is missing high end at the moment. Were NV will use two chips in Quadro/Tesla market AMD might need to use four with appalling efficiency and costs. That's a possibility that you should think about when you're speaking of multi-CPU servers.

    And can someone explain me why ATI earns zero on all these great small GPUs and NV earns nearly the same on that big ugly GT200 now selling in cards for less than $200? I've always had a problem with that pricing argument since it's kinda always was "assumed" that RV770 is much better for AMD than GT200/b for NV from the pricing point of view but in reality i'm not seeing any results of this "greatness" in AMDs balance sheets -- ATI earned less in the 1Q09 than it did in the 1Q08 when all they had was RV670 against G92 and G80.

    Nobody is have to do anything. NVIDIA is doing what they believe will earn them money. AMD is doing the same. Whose way is the best -- we don't know. But what everyone should consider is that NV's way is essentially nothing more and nothing less than AMD's way plus big GPU dies for high-end/workstation/server markets. AMD has simply left that market segment.

    It's funny that you say this right after you've said why single big GPUs are neccessary after all.
     
    #778 DegustatoR, Apr 23, 2009
    Last edited by a moderator: Apr 23, 2009
  19. Tahir2

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    OK some quick maths and why a card like the 4850 was positioned where it was with particular reference to performance/price:

    Gross Profit on x amount sold relatively (figures taken out of the air for comparison like most figures in these threads - guesttimates):

    4870 X2

    $300

    x 10

    = $3000

    Gross Profit on 4870/4890

    $150

    x 100 = $15000

    Gross Profit on 4850

    $100

    x 1000 = $100000

    Given the above whilst the ultra high end is desirable if you look at what part actually sells in volume and makes the most overall profit then it is the sweetspot of the 4850 and maybe even below.

    The ultra high end is important however for marketing purposes to ensure that the trickle down effect is felt by the consumer - i.e. the card they are purchasing is of high pedigree.
     
  20. Scali

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    I suppose the same goes for nVidia, which explains why GT200 isn't really cutting into their business results overall. I guess the 9600 and 9800-variations are the bread-and-butter.
     
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