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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Zingam - Thursday, October 1, 2009 - link
Perhaps next gen consoles would be C++ based and not API based (what a great terminology). So in that sense DirectX won't matter like it won't matter on Larrabee because it will be emulated in software. Larrabee would not have any silicon dedicated to OpenGL or DirectX I think.Once GPUs get fast enough I guess they won;t be called Graphics processors anymore and will support APIs as software implementations.
marc1000 - Thursday, October 1, 2009 - link
well, perhaps... I was searching the web yesterday for info on the new consoles, it was kinda sad. if we do not get a new minimun-standard (a powerful console), then the PC games will not be that hard to run on PCs... then my old Radeon 3850 is still capable of running almost ALL games with "good enough" permformance (read: average 30-50fps on most of the console ports to PC).and so: no reason to upgrade! :-(
Dobs - Wednesday, September 30, 2009 - link
Personally I think Eyefinity will be remembered as the master stroke as well as first to implement DirectX 11. Nvidia may get 10 fps more in DirectX 11 in Q2 2010 but will still struggle until it has it's own version of Eyefinity.Current uber-cool for the cashed-up is Eyefinity and once you have 3 or 6 monitors you will only buy hardware that will support it. These 'cashed-up' PC gamers are usually Nvidia's favorite customers.
Nvidia needs flexible wrap-around OLED mega resolution monitors to come out yesterday, but I'm pretty sure that didn't happen... 5850 which supports 3 monitors came out yesterday. :P
SiliconDoc - Thursday, October 1, 2009 - link
Nvidia has supported FOUR monitors on say for instance, the 570i sli, for like YEARS dude.Just put in 2 nv cards, plug em up - and off you go, it's right in the motherboard manuals...
Heck you can plug in two ati cards for that matter.
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Anyway on the triple monitor with this 5870/50, the drivers are a mess, some having found the patch won't be for a month, then the extra $100 cable is needed, too, as some have mentioned, that ati has not included.
They're pissed.
Dobs - Thursday, October 1, 2009 - link
I'll be avoiding the extra $100 cable by getting DisplayPort monitors from the start. Also want to get ips monitor (i think) so that it will support the portrait mode.If I already had 3 non-DisplayPort monitors, I wouldn't mind shelling out for the DisplayPort adapter if that was my only expense. But if the adapter was flakey I'd be upset as well. I know multi-monitors have been around for years, but they've never been this easy to set-up... Even I could do it :P And the drivers will get better in time, and no doubt future games will look to include Eyefinity as well.
SiliconDoc - Thursday, October 1, 2009 - link
Well I do hope you have good luck and that you and your son enjoy it ( no doubt will if you manage get it), and it would be nice if you can eventually link a pic (likely in some future article text area) just because.I think eyefinity has an inherent advantage, cheaper motherboard possible, 3 on one card, and with 3 from the same card, you can have the concave wrap view going with easy setup.
I agree however with the comment that it won't be a widely used feature, and realize most don't even use both monitor hookups on their videocards that are already available as standard, since long ago, say the 9600se and before.
(I use two though, and I have to say it is a huge difference, and much, much better than one)
yacoub - Wednesday, September 30, 2009 - link
Wake up: 99% of people don't give a crap about Eyefinity. Not only do the VAST, VAST majority of customers have just one display, but those who do have multiple ones (like myself) often have completely different displays, not multiple of the same model and size. And then, even when you find that 0.1% of the customer base that has two or more identical monitors side-by-side, you have to find the ones who game on them. Then of those people, find the ones who actually WANT to have their game screen split across two monitors with a thick line of two display borders right in the middle of their image.Eyefinity is relevant to such an infinitesimally small number of people it is laughable every time someone mentions it like it's some sort of "killer app" feature.
Jamahl - Thursday, October 1, 2009 - link
thats why eyefinity has millions of youtube views already right.yacoub - Thursday, October 1, 2009 - link
because purchases are measured in YouTube views. wow, just... wow.ClownPuncher - Thursday, October 1, 2009 - link
It clearly means people are interested enough to look. Wow, just...wow.You don't like it, other people do. Get over it.