GeForce FX Architecture Explained 185
Brian writes "3DCenter has published one of the most in-depth articles on the internals of a 3D graphics chip (the NV30/GeForce FX in this case) that I've ever seen. The author has based his results on a patent NVIDIA filed last year and he has turned up some very interesting relevations regarding the GeForce FX that go a long way to explain why its performance is so different from the recent Radeons. Apparently, optimal shader code for the NV30 is substantially different from what is generated by the standard DX9 HLSL compiler. A new compiler may help to some extent, but other performance issues will likely need to be resolved by NVIDIA in the driver itself."
I wonder what a structured classroom approach... (Score:5, Interesting)
On the other hand... (Score:4, Interesting)
One assumption is probably wrong (Score:5, Interesting)
I understand that the article writers are trying to come up with reasons that the Nvidia part is wasting performance, but this doesn't make sense. No architect in this right mind would ever design a pipeline that becomes full before the first instruction can exit. The means that you are fetching much faster than you are retiring instructions. That means you will always have a pipeline stall at the frontend and you will always be wasting cycles. I think the designers would have checked something like that. You can't afford pipeline stalls to happen regularly.
Re:Anand tells the tale (Score:2, Interesting)
GeforceFX (Score:5, Interesting)
Honestly, I thought nVidia learned their lesson with the NV1 - don't make weird hardware.
Now, what has to be making GeforceFX owners worried is Gabe Newell's warning that the new Detonator drivers might be making illegitimate 'optimizations' and, furthermore, covering them up by rendering high quality screen captures.
Re:Say what (Score:4, Interesting)
The most complex part of a DX8 or DX9 chip is the Pixel Shader, so I'll concentrate on it. Nvidia spearheaded the development of PS1.1 for DX8.
Then ATI stole the show with PS1.4 (DX8.1), which is much closer to PS2.0 than PS1.1. At this point, ATI got Microsoft's ear -- ATI was ahead of Nvidia in implementing programmable shaders in graphics hardware.
So Microsoft had good reason to pay attention to ATI's ideas of DX9 (including how the HLSL should look like and what kind of assembly it should output), long before any Xbox 1 money issues with Nvidia, long before choosing the designer for Xbox 2 graphics/chipset.
I guess
Re:Say what (Score:2, Interesting)
I've never had this problem with Nvidia, so even if they are slower from time to time, I'll stick with a company that doesn't screw me.
I appreciate the fact that ATI is increasing competition these days, but they'll never get another cent of mine.
Re:But can you hack a GeForce like you can hack Ra (Score:2, Interesting)
Notice in the picture the arrangement of the memory chips AROUND the core.
http://www.newegg.com/app/ViewProduct.asp?
Re:I wonder what a structured classroom approach.. (Score:3, Interesting)
It's all obsolete and legacy now. But it gives you a good idea about how a current day graphics card is designed. Back then, the various components had to be implemented on separate chips (eg. RAMDAC's, clock oscillators, memory decoding, graphics).
TI also had the TMS34082 vector processor. You could have up to four of those in a slave/master configuration (a bit like the PS2 VU0 processor). The TMS34020 supported 1/2/4/8/16/24/32 bit pixel sizes and had a parallogram rendering instruction (Two of those allow you to render a triangle). If they had kept the product range going and allowed Moore's law to keep going, they would probably have been able to keep up with 3Dfx.
Intel also has the i860 [geocities.com] which combined the floating point and graphics processing onto a single chip. The Intel XEON chip still supports this instruction set.
If you can access the IEEE and ACM archives, you'll find out about dozens more such processors.
Presently, you should have a look at the OpenGL extension a href="http://oss.sgi.com/projects/ogl-sample/regi
Any Google search on these topics will provide an almost infinite list of topics.