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
Efficiency Gets Another Boon: Parallel Kernel Support
In GPU programming, a kernel is the function or small program running across the GPU hardware. Kernels are parallel in nature and perform the same task(s) on a very large dataset.
Typically, companies like NVIDIA don't disclose their hardware limitations until a developer bumps into one of them. In GT200/G80, the entire chip could only be working on one kernel at a time.
When dealing with graphics this isn't usually a problem. There are millions of pixels to render. The problem is wider than the machine. But as you start to do more general purpose computing, not all kernels are going to be wide enough to fill the entire machine. If a single kernel couldn't fill every SM with threads/instructions, then those SMs just went idle. That's bad.
GT200 (left) vs. Fermi (right)
Fermi, once again, fixes this. Fermi's global dispatch logic can now issue multiple kernels in parallel to the entire system. At more than twice the size of GT200, the likelihood of idle SMs went up tremendously. NVIDIA needs to be able to dispatch multiple kernels in parallel to keep Fermi fed.
Application switch time (moving between GPU and CUDA mode) is also much faster on Fermi. NVIDIA says the transition is now 10x faster than GT200, and fast enough to be performed multiple times within a single frame. This is very important for implementing more elaborate GPU accelerated physics (or PhysX, great ;)…).
The connections to the outside world have also been improved. Fermi now supports parallel transfers to/from the CPU. Previously CPU->GPU and GPU->CPU transfers had to happen serially.
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AlexWade - Wednesday, September 30, 2009 - link
How long have you been working for NVidia?taltamir - Thursday, October 1, 2009 - link
don't insult nvidia by insinuating that this zealot is their employeedzoni2k2 - Wednesday, September 30, 2009 - link
What the heck is wrong with you SiliconDoc?Since when is memory bandwidth main indicator of performance?!
For all I care Fermis memory bandwidth can be 999GB/s but what good is that if it's not used?
SiliconDoc - Friday, October 2, 2009 - link
I'm sure "it won't be used" because for the very first time "nvidia will make sure it "won't be used" becuase "they designed it that way ! " LOL--
You people are absolutely PATHETIC.
Now the greater Nvidia bandwith doesn't matter, because you don't care if it's 999, because... nvidia failed on design, and "it won't be used!"
ROFLMAO
Honestly, if you people heard yourselves...
I am really disappointed that the bias here is so much worse than even I had known, not to mention the utter lack of intellect so often displayed.
What a shame.
PorscheRacer - Wednesday, September 30, 2009 - link
Exactly! R600 had huge bandwidth but couldn't effectively use it; for the msot part. Is this huge bandwdth the GF300 has only able to be used in cGPU, or is it able to be used in games, too? We won't know till the card is actually reviewed a long while from now.SiliconDoc - Wednesday, September 30, 2009 - link
What a joke. The current GT200 responds in all flavors quite well to memory clock / hence bandwith increases.You know that, you have been around long enough.
It's great seeing the reds scream it doesn't matter when ati loses a category. (no actually it isn't great, it's quite sickening)
SiliconDoc - Wednesday, September 30, 2009 - link
Yes of course bandwith does not really matter when ati loses, got it red rooster. When nvidia is SO FAR AHEAD in it, it's better to say "it's not double"...LOL---
WHAT IS WRONG WITH YOU PEOPLE AND THE AUTHOR IS THE REAL QUESTION!
--
What is wrong with you ? Why don't you want to know when it's nvidia, when it's nvidia a direct comparison to ati's card is FORBIDDEN !
That's what the author did !
It was " a very adept DECEPTION" !
---
Just pointing out how you get snowballed and haven't a clue.
Rumors also speculated 4,000 data rate ddr5
4000x384/8 - 192 bandwith, still planty more than 153 ati.
CLEARLY though "not double 141" (nvidia's former number also conveniently NOT MEWNTIONED being so close to 153/5870 is EMBARRASSING) - is 282...
--
So anand knows it's 240, not quite double 141, short of 282.
DigitalFreak - Wednesday, September 30, 2009 - link
Looks like SnakeOil has another alias!therealnickdanger - Wednesday, September 30, 2009 - link
Agreed. That was refreshing!mapesdhs - Wednesday, September 30, 2009 - link
Blimey, I didn't know Ujesh could utter such things. :D When I knew
him in 1998 he was much more offical/polite-sounding (he was Product
Manager for the O2 workstation at SGI; I was using a loaner O2 from
SGI to hunt for OS/app bugs - Ujesh was my main contact for feedback).
The poster who talked about availability has a strong point. My brother
has asked me to build him a new system next week. Looks like it'll be
an Athlon II X4 620, 4GB RAM, 5850, better CPU cooler, with either an
AM3 mbd and DDR3 RAM or AM2+ mbd and DDR2 RAM (not sure yet). By heck
he's going to see one hell of a speed boost; his current system is a
single-core Athlon64 2.64GHz, 2GB DDR400, X1950Pro AGP 8X. :D My own
6000+ 8800GT will seem slow by comparison... :|
Ian.