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 - Thursday, October 1, 2009 - link
Yes that is quite disappointing, but the 3 million transistor count and ddr5 somewaht makes up for it, and the fact that we're told by the red roosters that even 153 bandwith is plenty or just a tiny bit shy, and with what it looks like the 384 bit ddr5 4000 or 4800 data GT300 will come in at 192 bandwith minimum, or more likely 240 bandwith, quite a lot higher than 153.6 for ati's 5870.---
So really, what should I believe now, 153 is really plenty except in a few rare instances, or what you say LOL @ Trolls should believe, that 192 or 240 is worse than 153 ?
--
You might LOL @ TRolls, but from my view, you just made an awful fool of yourself.
HINT: The ati 5870 is only 256bit, not 384, and not 512.
Now, look in the mirror and LOL.
sigmatau - Thursday, October 1, 2009 - link
I know the ATI cards have 256 bit connections dumb ass. I'm just using your logic (or lack of it.) ATI has been able to outperform Nvidia cards with their 256 bit connections so your point about bandwidth is meaningless idiot.Now go pull that G295 out your ass, ok?
SiliconDoc - Thursday, October 1, 2009 - link
Golly, that ddr5 has nothing to do with bandwith, right, you stupid idiot ?--
Talk to me about the 4850, you lame, near brain dead, doofus. It's got ddr3 on it.
---
See, that's the other problem for you idiotic true believers, NV is moving from 2248 data rate ram on up to 4800.
But you're so able to keep more than one tiny thought in your stupid gourd at once, you "knew that".
BTW, you're not doing what I'm doing, you're not capable of it.
Now that sourpussed last little whine by you, the 295, beats everything ati has, making your simpleton statement A BIG FAT JOKE.
moltentofu - Thursday, October 1, 2009 - link
My god silicondoc you aren't really succeeding here. At what purpose? To convince people not to buy ati cards? You are such a complete, massive ahole it makes me want to go out and buy ati cards in bulk just to spite you.I'm guessing that if nvidia PR ever watched you rant your all-caps rants they would politely request that you stop associating yourself with their product.
Go ahead everybody google "silicondoc" if you have a strong stomach. Talk about spreading yourself all over the tubes! This guy's fingerprint is unmistakeable. Looks like he got banned on the HondaSwap forums after 14 posts. Guess he sucks on every forum. Maybe anandtech could ban him?
SiliconDoc - Thursday, October 1, 2009 - link
I think every one of you, that instead of actually leaving me alone, or responding with a counter argument to my points, every one of you that merely got logged in, and ripped away at me with an insult ought to be BANNED.That's what really should happen. I make my complaints and arguments on article and cards and companies, and the lies I see about all those, and most, but not all of you, have no response other than a pure trolling, insulting put down.
Every single one of you that came in, and personally attacked me without posting a single comment about the article, YOU are the ones that need to be banned.
Your collective whining is pure personal attack, and instead of commenting on the article, your love or hate for it, you texted up and did one single thing, let loose a rant against me. Just because you could, just because you felt apparently, "it was taking the high road"... which is as ignorant as the lies I've pointed out.
Time for YOU PEOPLE to be banned.
(minus those of course that actually made counterpoints, wether or not they insulted me or complained when they did - because AT LEAST they actually were discussing points, and contributing to the knowledge and opinion groupings.
Like for instance Monkeypaw, who made a reply that wasn't a pure trolling hate filled diatribe like you just posted, having nothing to do with the article at all.
Take a look in the mirror then consider yourself fella.
bobvodka - Thursday, October 1, 2009 - link
In which case I request that YOU are banned for calling ME a liar when I did nothing beyond reply telling you how, on launch day, I ordered a HD5870 and had it the next day.SiliconDoc - Thursday, October 1, 2009 - link
Oh you're full of it again, you pretended your view is the world, and therefore lied your butt off, and in a smart aleck fashion, PERIOD, pretending everyone doesn't know a few trickled out, which if you had clue one, you'd KNOW I was the one who posted that very information on this site.Claiming anyting else, is plain stupid, smart alecky, and LYING.
Just because drunken bob got a card, he claims, on the morning, it shhipped that day, he had it immediately, and has been enojying it ever since, the whole world is satisfied with the paper launch, that "does not exist in bob's drunken vodka world" where who knows what day it is anyeway.
You know, you people are trash,and expecting anyone else to pretend you're not is asking for way too much.
shotage - Thursday, October 1, 2009 - link
SillyDuck - please tone it down. You're getting out of control again!tamalero - Thursday, October 1, 2009 - link
hu.. you'r the one insulting every people who doesnt share your opinion with your "RED ROOSTERS" and other stuff...you're really special Mr. Doc, but in the sad way.
SiliconDoc - Thursday, October 1, 2009 - link
What red roosters, there aren't any here I'm told. Just plain frank and honest people who tell the truth.So if I say red rooster, it cannot possibly mean anyone here, posting, lurking or otherwise, as I'm certain you absolutely know.
( not like coming down to your level takes any effort, there you are special, just for you, so you don't feeel so bad about yourself )