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
Dobs - Thursday, October 1, 2009 - link
I'm with the zorro - will be setting this up for my son pretty soon - he is an extreme gamer who has mentioned multiple monitors to me a few times over the last few months. Up until now I only had a vague idea on how I could accommodate his desire.... that has all changed since the introduction of Eyefinity.Finally - Thursday, October 1, 2009 - link
..pussy-whipped by your son?the zorro - Thursday, October 1, 2009 - link
moron, i am going to buy two more monitors and then... eyefinity.chizow - Wednesday, September 30, 2009 - link
Nvidia didn't mention anything about multi-monitor support, but today's presentation wasn't really focused on the 3D gaming market and GeForce. They did spend a LOT of time on 3D Vision though, even integrating it into their presentation. They also made mention of the movie industry's heavy interest in 3D, so if I had to bet, they would go in the direction of 3D support before multi-monitor gaming.It wouldn't be hard for them to implement it though if they wanted to or were compelled to. Its most likely just a simple driver block or code they need to port to their desktop products. They already have multi-monitor 3D on their Quadro parts and have supported it for years, its nothing new really, just new on the desktop space with Eyefinity. It then becomes a question if they're willing to cannibilize their lucrative Quadro sales to compete with AMD on this relatively low-demand segment. My guess is no, but hopefully I'm wrong.
Dobs - Thursday, October 1, 2009 - link
I think Nvidia are underestimating the desire and affordability for multi-monitor gaming. Have you seen monitor prices lately? Have you seen the Eyefinity reviews?By not making any mention of it is a big mistake in my book. Sure they can do it, but it will reduce there margins even further since they obviously hadn't planned spending the extra dollar$ this way.
I do like the sound of the whole 3D thing in the keynote though... and everyone wearing 3D glasses...(not so much). But it will be cool once the Sony vs Panasonic vs etc.? 3D format war is finished, (although it's barely started) so us mainstream general consumers know which 3D product to buy. Just hope that James Cameron Avatar film is good :)
chizow - Thursday, October 1, 2009 - link
Yeah I've seen the reviews and none seemed very compelling tbh, the 3-way portrait views seemed to be the best implementation. 6-way is a complete joke, unless you enjoy playing World of Bezelcraft? There's also quite a few problems with its implementation as you alluded to, the requirement of an active DP adapter was just a short-sighted half-assed implementation by AMD.As Yacoub mentioned, the market segment for people interested or willing to invest in this technology is so ridiculously small, 0.1% is probably pretty close to accurate given multi-GPU technology is estimated to only be ~1% of the GPU market. Surely those interested in multi-monitor is below that by a significant degree.
Still for a free feature its definitely welcome, even in the 2D productivity sense, or perhaps for a day trader or broker....or anyone who wanted to play 20 flops simultaneously in online poker.
Dobs - Thursday, October 1, 2009 - link
Lol @ 20 flops simultaneously in online poker. I struggle with 4 :)Agree with 6 monitor bezelcraft - Cross hair is the bezel :)
I guess I'm lucky that my son is due for a screen upgrade anyhow so all 3 monitors will be new. Which one will be the problem - I hear Samsung are bringing out small-bezel monitors specifically for this, but I probably can't wait that long. (Samsung LED looks awesome though) I might end up opting for 3 of Dell's old (2008) 2408WFP's (my work monitor) as I know I can get a fair discount for these and I think they have DisplayPort. I'm not sure if my son will like Landscape or Portrait better but I want him to have the option... and yeah apparently the portrait drivers are limited (read crap) atm.
Appreciate your feedback as well as your comments on the 5850 article... I actually expected the GT prices to be $600+ not the $500-$550 you mentioned. Oops... rambling now. Cheers
chizow - Thursday, October 1, 2009 - link
Heheh I've heard of people playing more than 20 flops at a time....madness.Anyways, I'm in a similar holding pattern on the LCD. While I'm not interested in multi-monitor as of now, I'm holding out for LED 120Hz panels at 24+" and 1920. Tbh, I'd probably check out 3D Vision before Eyefinity/multi-monitor at this point, but even without 3D Vision you'd get the additonal FPS from a 120Hz panel along with increased response times from LED.
If you're looking to buy now for quality panels with native DP support, you should check out the Dell U2410. Ryan Smith's 5870 review used 3 of them I think in portrait and it looked pretty good. They're a bit pricey though, $600ish but they were on sale for $480 or so with a 20% coupon. If you called Dell Sm. Biz and said you wanted 3 you could probably get that price without coupon.
As for GTX 380 price, was just a guess, Anand's article also hints Nvidia doesn't want to get caught again with a similar pricing situation as with GT200 but at the same time, relative performance ultimately dictates price. Anyways, enjoyed the convo, hope the multi-mon set-up works out! Sounds like it'll be great (especially if you like sims or racing games)!
RadnorHarkonnen - Thursday, October 1, 2009 - link
Eyefinity is screaming for DIY.Bezel Craft can be easly avoided. Just tear you monitor apart. A stand for 3 monitors is easly ordered/DIY made. Ussually the bezel is way thicker than it need to be.
Unfortunely i alreayd have a 4850 CF that i will keep for more a year or two and let the tecnology mature for now.
wifiwolf - Wednesday, September 30, 2009 - link
Can we have a new feature in the comments please?I just get tired of reading a few comments and get bugged by some SiliconDoc interference.
Can we have a noise filter so comments area gets normal again.
Every graphics related article gets this noise.
Just a button to switch the filter on. Thanks.