Originally Posted by lukilla
Zero improvement for me but thanks...
I was afraid of this.
This is so odd.
Funnily enough my GPU is almost never begin used 100% as I've monitored. Even at night races it often lingers around 74% while the FPS stays at 47-50. Occasionally there are also 1 second dips to 20 FPS. It's very random. They have no impact in game (such a sudden freeze), but I find it odd that it happens. I believe it has something to do with loading in new textures and stuff.
It's possible that due to low memory clock there's no data to work with and that's why GPU semi-idles. As it has been stated 512MB is kinda the minimal amount for smooth play. Or perhaps it's the capacity instead. For example, 512MB contains all
of the data necessary for rendering the scene around you. However, if you'd have 1GB of memory it would render things that are further ahead thus using the "left-over" processing power.
If it is what I think it is then it has been programmed very cleverly and it means I may turn on higher settings. I wont gain nor lose anything. I'm merely tightening the "barrier" so that less is being rendered "ahead" thus forcing the GPU to do more work, more often.
I think that regardless of the amount of processing power you have, the actual use of it is being limited by the memory. If that's the case then it's very clever, because you can tweak the settings until you hit the zone where GPU usage averages around 90%. This leaves some room for play in more intense situations where that 10% might help to keep the FPS smooth. Think of it as a nitro. Extra boost just in case you need it.
Very interesting indeed...I need to do more testing.
Edit : Very intriguing. Monitoring CPU usage, it stays around 50%. Funnily enough, CPU usage dropped by 20% when turning on AA. However, GPU usage went up to 99-100% all the time. That is AA on normal. Without AA GPU averages around 70%. Considering the fact that FPS drops by about ~17 FPS means that AA eats up more than 30%.
If they will move AA over to CPU it will fix many problems!
Setting affinity to only two cores brings up the CPU usage to around 90%. With 16 cars, lots of collision, etc two cores may stay a bit weak, but generally three cores should be enough to run this game just fine. One core is pretty much free and can easily be used for AA.
No, wait, I could be wrong. The moment you turn the wheel CPU usage jumps by 30-50% or even more. Basically all the physics and stuff come into play. Funnily enough when just applying acceleration, going straight and not using the wheel, CPU averages around 40%, touch the wheel and it jumps to 70-85%. Fascinating stuff.
Edit 2 : More interesting stuff! I found the zone by lowering track detail to low and increasing shadows to high. This kept the GPU at ~98%. This is not exactly what I'd call ideal, but according to my discoveries I'm about to tell you now it's irrelevant anyway.
Well, it really does look as if the limit is caused by the capacity of the memory or the clock. What I found out that while driving solo is that I got solid 60 FPS with GPU usage averaging around 98%. I expected a chaos in an actual race. So, I booted up a race and what comes out is that GPU usage averages around 60-75%(!) while keeping the FPS around 30. CPU idles around 40%, lol.
Anyways, this tells me few things. Either it's the HDD (unlikely as I've monitored the usage and it's stable since most of the necessary stuff has already been loaded on the RAM), RAM (unlikely, because RAM usage stays stable turning the race) or the actual graphics card VRAM and/or memory clock speed. The limit is thus caused by the VRAM not being able to keep up the constant requests. Keep in mind that higher resolution shadow maps require more space which in turn leaves less space for textures and all the rest. So, what I'm going to now is concentrate on overclocking the VRAM only and see if there's any change whatsoever.
In theory this should help the game adjust faster to rapid changes thus providing more data to the GPU to work with, but if the process is heavily prioritized by programmers then nothing is being dumped until they're no longer needed. This means that overclocking won't do a thing or has very, very insignificant change. The only thing that would help in this case would be increasing VRAM (getting a new card).
This is obviously all just a theory...