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.
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SiliconDoc - Wednesday, September 30, 2009 - link
I'm sure Anand brought it out of him with his bias.Already on page one, we see the UNFAIR comparison to RV870, and after wailing Fermi "not double the bandwidth" - we get ZERO comparison, because of course, ATI loses BADLY.
Let me help:
NVIDIA : 240 G bandwidth
ati : 153 G bandwidth
------------------------nvidia
---------------ati
There's the bandwidth comparison, that the biased author couldn't bring himself to state. When ati LOSES, the red fans ALWAYS make NO CROSS COMPANY comparison.
Instead it's "nvidia relates to it's former core as ati relates to it's former core - so then "amount of improvement" "within in each company" can be said to "be similar" while the ACTUAL STAT is "OMITTED !
---
Congratulations once again for the immediate massive bias. Just wonderful.
omitted bandwith chart below, the secret knowledge the article cannot state ! LOL a review and it cannot state the BANDWITH of NVIDIA's new card! roflmao !
------------------------nvidia
---------------ati
NVIDIA WINS BY A VERY LARGE PERCENTAGE.
konjiki7 - Friday, October 2, 2009 - link
http://www.hardocp.com/news/2009/10/02/nvidia_fake...">http://www.hardocp.com/news/2009/10/02/..._fakes_f...
Samus - Thursday, October 1, 2009 - link
Thats great and all nVidia has more available bandwidth but....they're not anywhere close to using it (much like ATi) so exactly what is your point?SiliconDoc - Friday, October 2, 2009 - link
Wow, another doofus. Overclock the 5870's memory only, and watch your framerates rise. Overclocking the memory increases the bandwith, hence the use of it. If frames don't rise, it's not using it, doesn't need it, and extra is present.THAT DOESN'T HAPPEN for 5870.
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Now, since FERMI has 40% more T in core, and an enourmous amount of astounding optimizations, you declare it won't use the bandwith, but your excuse was your falsehood about ati not using it's bandwith, which is 100% incorrect.
Let's pretend you meant GT200, same deal there, higher mem oc= more band and frames rise well.
Better luck next time, since you were 100% wrong.
mm2587 - Thursday, October 1, 2009 - link
you do realize the entire point of mentioning bandwidth was to show that both Nvidia and AMD feel that they are not currently bandwidth limited. They have each doubled their number of cores but only increased bandwidth by ~%50. Theres no mention of overall bandwidth because thats not the point that was being made. Just an off hand observation that says "hey looks like everyone feels memory bandwidth wasn't the limitation last time around"Zingam - Thursday, October 1, 2009 - link
ATI has it here and has it now! NVIDIA does not win because on paper I have 50 billion transistors GPU on 1 nm process! I win! ;)You are a retarded fanboy! And I am not. I'd buy what's best for my money.
SiliconDoc - Thursday, October 1, 2009 - link
Behold the FERMI GPU unbeliever !http://www.fudzilla.com/content/view/15762/1/">http://www.fudzilla.com/content/view/15762/1/
That's called, COMPLETED CARD, RUNNING SILICON.
Better luck next time incorrect ignorant whining looner.
siyabongazulu - Friday, October 2, 2009 - link
Do you see any captions on that site? I don't think so. Nowhere does it mention that it's a complete card. So please stop lying because that goes to show how ignorant you are. Any person with a sound mind can and will tell you that it's not a finished product. So come up with something more valid to show and rant about. Sorry that your big daddy Heung hasn't given you your green slime if you like it that way. Just wait on the corner and when he says, GT300 is a go and tests confirm that it trumps 5870 then you can stop crying and suck on that.silverblue - Thursday, October 1, 2009 - link
When's it coming out?I mean, you have all the answers.
SiliconDoc - Thursday, October 1, 2009 - link
Well thanks for the vote of confidence, but yesterday on the launch, according to the author, right ?LOL
Ha, golly, what a pile.