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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  • silverblue - Thursday, October 1, 2009 - link

    Am I hearing you right - you say GT300 isn't a paper launch despite there being no cards for sale for the next few months, yet you said the 5870 was AND THERE WERE CARDS FOR SALE WHEN YOU MADE THE COMMENT! I don't care that you couldn't locate one, the simple fact is people had already bought cards from the first trickle (emphasis on the trickle part) and as such made your statement completely invalid.

    How much more rubbish are you going to spew from your hole?

    (note: I needed to have caps above to make a salient point and not just because I felt like holding the shift key for no particular reason)
  • SiliconDoc - Thursday, October 1, 2009 - link

    roflmao - If you're hearing anything right, you'd keep your text yap shut.
    Please show me the LAUNCH information on GT300, there, brainless bubba, the liar. I really cannot imagine you are that stupid, but then again, it is possible.

    Congratulations for being a COMPLETE IDIOT AND LIAR! Really, you must work very hard to maintain that level of ignorance. In fact, the requirement to be that stupid exceeds the likelihood that you actually are purely ignorant, and therefore, it is more likely you're a troll. My condolences in either case in all seriousness.
  • silverblue - Thursday, October 1, 2009 - link

    The proposed launch is late November but even Fudzilla concede that any problems will delay this. The earliest we'll see a GT300 on the shelves is just under 2 months. There, that's information for you. I want nVidia to launch GT300 this year but we don't always get what we wish for.

    Where did I lie in any of my previous posts? Oh right... I didn't bow down to worship the Green God(dess). If you had any semblance of an open mind or any stability at all, your nose wouldn't need cleaning. Calling me a troll is pure comedy gold and offering me your pity is outstanding to say the least :)

    Keep trying. Or don't. Either way, I doubt many people care for your viewpoints anymore.
  • SiliconDoc - Thursday, October 1, 2009 - link

    Oh jeeze, one red rooster who finally gets it.
    Congratulations, you're not the dumbest of your crowd.
    --
    No shirking here comes the QUOTE !

    " The proposed launch is late November " !!! whoo hoo !

    Now a proposed launch is not an official launch- try to keep that straight in the gourd haters when the time comes.
    --
    Pass it along to all the screaming tards, won't you please, you talk their language, or perhapos we'll just say you already have, because, by golly, they can believe you.
    ROFLMAO
  • rennya - Thursday, October 1, 2009 - link

    'Nvidia LAUNCHED TODAY... se page two by your insane master Anand.'


    This what you have said yourself somewhere in this very discussion. So you must have known about this so-called launch yourself.
  • SiliconDoc - Thursday, October 1, 2009 - link

    That's called sarcasm dear. Jiminy crickets.
  • palladium - Thursday, October 1, 2009 - link

    How can you tell if that's not a GTX285 with redesigned cover/cooler/PCB?
  • samspqr - Monday, October 5, 2009 - link

    it is SO funny that that thing silicondoc's master/god is holding in his hand ended up revealing itself as nothing more than a mock-up...
  • SiliconDoc - Wednesday, September 30, 2009 - link

    PS THE SILICON IS ALREADY CUT AND IN PRODUCTION!
    ---
    Yes anand at the bottom of page 1 claims "it's paper" - DECIEVING YOU, since the WAFERS HAVE ALREADY BEEN BURNED AND YIELDS ARE REPORTED HIGH ! (in spite of ati's marketing arm lying and claiming "only 9 cores per wafer yields" - A BIG FAT LIE NVIDIA POINTED OUT !
    Where have you been with your head in the sand ?
    --
    So at the bottom of page 1 Anand leaves you dips with the impression "it's all paper" (but the TRUTH is DEVELOPER CARDS ARE ALREADY ASSEMBLED and being DEBUGGED and TESTED) just anand won't get one for 2 months.
    ---
    THEN BY PAGE 2 ANAND CALLS IT A PAPER LAUNCH !
    roflmao
    Yes, the red rooster himself has convinced himself "today's nvidia LAUNCH" (that LAUNCH word is what anand made up in his deranged mind) is a paper launch "JUST LIKE ATI'S!".
    ---
    It is nothing short of absolutely AMAZING.
    The red rooster fan has boonswoggled his own gourd, stated in fasle terms, bashed it to be as bad as what ati just did with 5870, and IT'S NOT EVEN A LAUNCH DAY FOR NVIDIA !
    ---
    Congratulations, the massive bias is SCREAMING off the page. LOL
    It's hilarious, to say the least, that the master can be that deluded with his own spew!
  • gx80050 - Friday, October 2, 2009 - link


    Die painfully okay? Prefearbly by getting crushed to death in a
    garbage compactor, by getting your face cut to ribbons with a
    pocketknife, your head cracked open with a baseball bat, your stomach
    sliced open and your entrails spilled out, and your eyeballs ripped
    out of their sockets. Fucking bitch


    I would love to kick you hard in the face, breaking it. Then I'd cut
    your stomach open with a chainsaw, exposing your intestines. Then I'd
    cut your windpipe in two with a boxcutter.
    Hopefully you'll get what's coming to you. Fucking bitch




    I really hope that you get curb-stomped. It'd be hilarious to see you
    begging for help, and then someone stomps on the back of your head,
    leaving you to die in horrible, agonizing pain. Faggot


    Shut the fuck up f aggot, before you get your face bashed in and cut
    to ribbons, and your throat slit.

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