Efficiency Gets Another Boon: Parallel Kernel Support

In GPU programming, a kernel is the function or small program running across the GPU hardware. Kernels are parallel in nature and perform the same task(s) on a very large dataset.

Typically, companies like NVIDIA don't disclose their hardware limitations until a developer bumps into one of them. In GT200/G80, the entire chip could only be working on one kernel at a time.

When dealing with graphics this isn't usually a problem. There are millions of pixels to render. The problem is wider than the machine. But as you start to do more general purpose computing, not all kernels are going to be wide enough to fill the entire machine. If a single kernel couldn't fill every SM with threads/instructions, then those SMs just went idle. That's bad.


GT200 (left) vs. Fermi (right)

Fermi, once again, fixes this. Fermi's global dispatch logic can now issue multiple kernels in parallel to the entire system. At more than twice the size of GT200, the likelihood of idle SMs went up tremendously. NVIDIA needs to be able to dispatch multiple kernels in parallel to keep Fermi fed.

Application switch time (moving between GPU and CUDA mode) is also much faster on Fermi. NVIDIA says the transition is now 10x faster than GT200, and fast enough to be performed multiple times within a single frame. This is very important for implementing more elaborate GPU accelerated physics (or PhysX, great ;)…).

The connections to the outside world have also been improved. Fermi now supports parallel transfers to/from the CPU. Previously CPU->GPU and GPU->CPU transfers had to happen serially.

A More Efficient Architecture ECC, Unified 64-bit Addressing and New ISA
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  • SiliconDoc - Friday, October 2, 2009 - link

    Yeah, of course, 3 million T core, and it doesn't need much bandiwth, and it won't be used, perhaps, or probably, because the GPU designers haven't a clue, and of course, you do.
    ---
    Another amazing clown with a red nose. You people really should stop typing stupid stuff like that.
  • Calin - Sunday, October 4, 2009 - link

    There was no performance improvement from increasing the bandwidth of the Athlon64 processors due to the move to DDR2 memory (a theoretical doubling of performance, with about one and a half more measured bandwidth in the first generation of the processor).

    I might not have a clue, but do you?
  • SiliconDoc - Wednesday, September 30, 2009 - link

    Very interesting of course, and so with your theory, it could also be LOWER, with slower ddr5, but the fact REMAINS, 240 has ALREADY BEEN LEAKED.
    so we know what it is, and Anand KNOWS IT'S MORE, BUT NOT DOUBLE AND SAYS SO !
    ---
    SO WHAT WE HAVE IS A CONVENIENT COVER UP. PERIOD!
    --
    JUST NOT AS STUPID AS YOU, THAT'S ALL.
  • dragunover - Thursday, October 1, 2009 - link

    "SO WHAT WE HAVE IS A CONVENIENT COVER UP. PERIOD!
    --
    JUST NOT AS STUPID AS YOU, THAT'S ALL. "
    I disregarded anything you said before and after that.
  • SiliconDoc - Friday, October 2, 2009 - link

    I'm certain you attempted it, as you no doubt love to wallow in blissful ignorance and denial just by mere unchangeable habit.
    But having read it, you have nowhere to go. Your mind is already irreparably altered. Congratulations.
  • jonGhast - Wednesday, September 30, 2009 - link

    True, you seem to be a whole new level of stupid.
  • mapesdhs - Wednesday, September 30, 2009 - link


    I have a theory on that one: faulty keyboard. Every time he hits Shift
    to get upper case, his keyboard is zapping out brain cells with EMF bursts. :D

    Best to just ignore & not reply IMO.

    Ian.

  • SiliconDoc - Thursday, October 1, 2009 - link

    Well you can't ignore the discussion, and as far as that goes, you want everyone else to do your will, as you beg for it, with your empty advice, which is by the way, all you provided in the last thread.
    So you quack around telling others not to participate. That's your whole gig mary.

    I find the stupidity level amazing, as most of you can only spew in and beg eachother not to comment, and by the quality of the comments that actually try a counter, I certainly cannot blame you, for begging others to surrender ahead of time.

    You notice how many new names are here ? lol
    It's clear who and what it is that responds, and what level of conduct they are all about.

    Now let's see the Sybillic mapes sign off on his/her own glorious advice, which she/he failed to follow already.
  • Silverel - Thursday, October 1, 2009 - link

    Hey buddy. Take a pill and relax.

    Your product isn't on the market yet. There's no recommendation to be heeded. It doesn't matter how fast it is, you can't have one. No one can. If someone wants to get their next-gen performance on now, ATI is what you'll buy.

    It's okay though. Not everyone is going to run out and grab an ATI card. There's plenty of people that will wait for hell to freeze over for nVidia to release a new card. Personally, I'll take the Q1 2010 release date as semi-fact, but hell freezing over is my fallback date.

    So feel free to continue ranting like you've run out of meds. Insult anyone who has made a comment contrary to your own. It's not really doing you any favors, but that's okay. I'm sure it's having an effect on the opinions of people sitting on the fence. Ah, and just to dig the finger in the wound, you can consider me an ATI shill, just for good measure.

  • SiliconDoc - Thursday, October 1, 2009 - link

    Gosh you';re a sweetheart, too, and wrong ! WRONG ! WRONG !

    the red bloviator> " . If someone wants to get their next-gen performance on now, ATI is what you'll buy. "

    Gee, did you lose it that easily, was your heart beating so hard, were you sweaty, and upset, and out of control, and decided it was great to tell me to settle down, when your brain was on FART ?

    Please see the GTX295 that BEATS the 5870. The 5870 is PRIOR GEN performance - as ati's own 4870x2/or CF is equal.

    Golly, what a deal, another red rooster massive ruse.

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