Quote Originally Posted by annihilat0r View Post
But then, if gaming-related enhancements and differences of GF100 are adding shader units and stuff, how do you account for the incredible performance differences between games? One game it tramples 5870, one game it falls behind with 2x transistors.

Some guys at B3D have pointed out that this is related to how geometry intensive a game is. Apparenetly FC2 is such a game whereas Crysis is just shader/texturing intensive, thus accounting for the big performance difference.

And if this is true, it should mean that GF100 is architecturally very different.
This is related to how the game is written. Most performance-increases could be achieved by optimizing the game, no optimizing the drivers. This is too much overestimated way, but wrong way and for that reason we see mostly few percent increases.

I give Unreal Engine as an example every time: as Epic presented on GDF 2008, they focus on optimizing the engine/games before it is released, because it is cheaper. They e.g. have several machines running the game 24/7 and logging it. When somewhere is performance drop, they focus on the reason. We all know Bioshock looks pretty good and runs smoothly on almost everything DX10 capable (if you not count GF8400/HD 3450 as a DX10 capable). This is probably last developer doing this, others usually roll it out with critical bugs and don't care. But it pays off since UE is the most common engine.

And of course this means also how the engine works. For example old games often used post-proces rather than advanced shader features, so they do not perform much better on Radeon X800 or HD 3870. F.E.A.R. is example I remember since I play it when I have time now (once a week or so); I am used to play on 20 FPS average, but this game sometimes falls under 20 FPS even with HD 3870@915 MHz, Windsor 2,8 GHz.

You should also not forget on how AMD's stream processors work: if the SP are feeded optimaly, up to 5 instructions could be processed. If not, you gain performance drop. Than it is huge difference if you feed 3 or 5 instruction on average making the Radeons somewhere win, somewhere lose.