NVIDIA's Fermi: Architected for Tesla, 3 Billion Transistors in 2010
by Anand Lal Shimpi on September 30, 2009 12:00 AM EST- Posted in
- GPUs
ECC Support
AMD's Radeon HD 5870 can detect errors on the memory bus, but it can't correct them. The register file, L1 cache, L2 cache and DRAM all have full ECC support in Fermi. This is one of those Tesla-specific features.
Many Tesla customers won't even talk to NVIDIA about moving their algorithms to GPUs unless NVIDIA can deliver ECC support. The scale of their installations is so large that ECC is absolutely necessary (or at least perceived to be).
Unified 64-bit Memory Addressing
In previous architectures there was a different load instruction depending on the type of memory: local (per thread), shared (per group of threads) or global (per kernel). This created issues with pointers and generally made a mess that programmers had to clean up.
Fermi unifies the address space so that there's only one instruction and the address of the memory is what determines where it's stored. The lowest bits are for local memory, the next set is for shared and then the remainder of the address space is global.
The unified address space is apparently necessary to enable C++ support for NVIDIA GPUs, which Fermi is designed to do.
The other big change to memory addressability is in the size of the address space. G80 and GT200 had a 32-bit address space, but next year NVIDIA expects to see Tesla boards with over 4GB of GDDR5 on board. Fermi now supports 64-bit addresses but the chip can physically address 40-bits of memory, or 1TB. That should be enough for now.
Both the unified address space and 64-bit addressing are almost exclusively for the compute space at this point. Consumer graphics cards won't need more than 4GB of memory for at least another couple of years. These changes were painful for NVIDIA to implement, and ultimately contributed to Fermi's delay, but necessary in NVIDIA's eyes.
New ISA Changes Enable DX11, OpenCL and C++, Visual Studio Support
Now this is cool. NVIDIA is announcing Nexus (no, not the thing from Star Trek Generations) a visual studio plugin that enables hardware debugging for CUDA code in visual studio. You can treat the GPU like a CPU, step into functions, look at the state of the GPU all in visual studio with Nexus. This is a huge step forward for CUDA developers.
Nexus running in Visual Studio on a CUDA GPU
Simply enabling DX11 support is a big enough change for a GPU - AMD had to go through that with RV870. Fermi implements a wide set of changes to its ISA, primarily designed at enabling C++ support. Virtual functions, new/delete, try/catch are all parts of C++ and enabled on Fermi.
Facebook
Twitter
RSS
415 Comments
View All Comments
LawRecordings - Thursday, October 1, 2009 - link
Buwahahaha!!!What a sad, lonely little life this Silicon Doc must lead. I struggle to see how this guy can have any friends, not to mention a significant other. Or even people that can stand being in a room with him for long. Prolly the stereotypical fat boy in his mom's basement.
Careful SD, the "red roosters" are out to get you! Its all a conspiracy to overthrow the universe, and you're the only one that knows!
Great article Anand, as always.
Regards,
Law
Vendor agnostic buyer of the best price / performance GPU at the time
SiliconDoc - Thursday, October 1, 2009 - link
They can't get me, they've gotten themselves, and I've just mashed their face in it.And you're stupid enough to only be able to repeat the more than thousandth time repeated internet insult cleche's, and by your ignorant post, it appears you are an audiophile who sits bouncing around like a retard with headphones on, before after and during getting cooked on some weird dope, a HouseHead, right ? And that of course does not mean a family, doper.
So you giggle like a little girl and repeat what you read since that's all the stoned gourd can muster, then you kiss that rear nice and tight, brown nose.
Don't forget your personal claim to utter innocence, either, mr unbiased.
LOL
Yep there we have it, a househead music doused doped up butt kisser with a lame cleche'd brain and a giggly girl tude.
Golly, what were you saying about wifeless and friendless ?
ClownPuncher - Thursday, October 1, 2009 - link
What exactly is a cleche?Is it anything like a cliche?
Your spelling, grammar, and general lack of communication skill lead me to think that you are actually a double agent, it's an act if you will...an ATI guy posing as a really socially stunted Nvidia fan in an attempt to turn people off of Nvidia products solely by the ineptitude of your rhetoric.
UNCjigga - Wednesday, September 30, 2009 - link
I'd hate to have a political conversation with SiliconDoc, but I digress...Some very interesting information came out in today's previews. Will Fermi be a bigger chip than Cypress? Certainly. Will it be more *powerful* than Cypress? Possibly. Will it be more expensive than Cypress? Probably. Will it have more memory bandwidth than Cypress? Yes.
Will it *play games* better than Cypress? Remains to be seen. Too many factors at play here. We don't know clock speeds. We have no idea if "midrange" Fermi cards will retain the 384-bit memory interface. We have
For all we know, all of Fermi's optimizations will mean great things for OpenCL and DirectCompute, but how many *games* make use of these APIs today? How can we compare DirectX 11 performance with few games and no Fermi silicon available for testing? Most of the people here will care about game performance, not Tesla or GPGPU. Hell, its been years since CUDA and Stream arrived and I'm still waiting for a decent video encoding/transcoding solution.
Calin - Thursday, October 1, 2009 - link
Even between current cards (NVIDIA and AMD/ATI) the performance crown moves from one game to another - one card could do very well in one game and much worse in another (compared to the competition). As for not yet released cards, performance numbers in games can only be divined, not predictedBull Dog - Wednesday, September 30, 2009 - link
So how much in NVIDIA's focus group partner paying you to post this stuff?dzoni2k2 - Wednesday, September 30, 2009 - link
You seriously need to take your medicine. And call your shrink.dragonsqrrl - Thursday, October 1, 2009 - link
I know it seems like SiliconDoc is going on a ranting rage, because he kinda is, but the fact remains that this was a fairly biased article on the part of Anandtech. I've been reading reviews and articles here for a long time, and recently there has been a certain level of prejudice against Nvidia and its products that I haven't noticed on other legitimate review cites. This seems to have been the result of Anandtech getting left out of the loop last year. Throughout the article there is a pretty obvious sarcastic undertone towards what the Nvidia representatives say, and their newly announced GPU. I can only hope that this stops, so that anandtech can return to its former days of relatively balanced and fair reporting, which is all anyone can ask of any legitimate review cite. Articles of this manner and tone serve no purpose but to enrage people like SiliconDoc, and hurt Anandtech's image and reputation as a balanced a legitimate tech cite.Keeir - Thursday, October 1, 2009 - link
Curious in where you see the Bias.I see a little bit of the tone, but it seems warranted for a company that has for the last few years over-promised and under delivered. Very similar to how AMD/ATI was treated upto the release of the 4 series. Nvidia needs to prove (again) that it can deliever a real innovative product priced at an affordable level for the core audience of graphics cards.
Here we are, 7 days after 5870 launch and Egg has 5870s for ~375 to GTX 295s at 500. Yet again, ATI/AMD has made it a puzzling choice to buy any Nvida product more than 200 dollars.... for months at a time.
SiliconDoc - Friday, October 2, 2009 - link
What's puzzling is you are so out of touch, you don't realize the GTX295's were $406 before ati launched it's epic failure, then the gtx295 rose to $469 and the 5870 author edsxplained in text the pre launch price, and now you say the GTX295 is at $500.Clearly, the market has decided the 5870 is epic failure, and instead of bringing down the GTX295, it has increased it's value !
ROFLMAO
Awwww, the poor ati failure card drove up the price of the GTX295.
Awww, poor little red roosters, sorry I had to explain it to you, it's better if you tell yourself some imaginary delusion and spew it everywhere.