Quote from Gunn :

you don't need to run that high to enjoy LFS.

No, of course not . But the point is that it's quite easy to bog down a 7600GT/8600GT in LFS if you up the resolution and AA/AF, and I'm certain that's the problem in Boris' case.

Quote from wien :

No, of course not . But the point is that it's quite easy to bog down a 7600GT/8600GT in LFS if you up the resolution and AA/AF, and I'm certain that's the problem in Boris' case.

Well, i can lower the AA but i can't help but think that it shouldn't be like that. All i'm saying is, "god forbid" that we have advancier graphics, like some more polygons on the cars for starters, pixel shaders, rain, what system would you have to have in order to work fine on start with ~15, 20 cars?

Quote from Boris Lozac :

All i'm saying is, "god forbid" that we have advancier graphics, like some more polygons on the cars for starters, pixel shaders, rain, what system would you have to have in order to work fine on start with ~15, 20 cars?

That's the ting. You could easily add very advanced pixel shaders to LFS' current graphics without taking ANY hit in FPS. The way LFS is currently using the GPU the actual shader pipeline is not really doing much work and on modern cards there is a hell of a lot of headroom there. The bottleneck is elsewhere on the graphics card (most likely memory bandwidth) and that doesn't have to change when adding more realistic shaders.

Once you have a bottleneck somewhere in a system like this, increasing the workload on any other part of the system won't really have any effect on performance. The GPU isn't some black box with finite performance. Depending on the workload different parts of the GPU may be the thing holding it back.

Quote from Jakg :

If your using any AA that 8600 is easily the thing that's holding you back.

*sigh* I've said it for years, Jakg, but you never listen. What really matters in LFS is minimum framerate, which usually occurs when there are lots of cars on the screen in close proximity. The main component limiting minimum framerate for me has always been the CPU. The one exception was my GF 4600. When I got a 6800GT, the performance without AA was the same, but I was able to run 4xAA with no performance hit.

So to summarize:
CPU = Athlon XP 3000+ (2.1GHz)
LFS average framerate: 4600 (no AA) = 6800GT (no AA) = 6800GT (4xAA)

Obviously the minimum framerate was also the same because the CPU didn't change.

When I got my new system (C2D 2.13GHz, 7900GT), I compared the difference in minimum framerate between 2.13GHz and 3.2GHz (a 50% increase). I ended up with a perfect 50% increase in minimum framerate. How's that for being "GPU limited"?

Quote from Forbin :

So to summarize:
CPU = Athlon XP 3000+ (2.1GHz)
LFS average framerate: 4600 (no AA) = 6800GT (no AA) = 6800GT (4xAA)

Obviously the minimum framerate was also the same because the CPU didn't change.

Absolutely, but on my (old) Athlon XP 3000+ with a 7600GT running with 8X AA at 1920x1200 caused a significant FPS drop meaning it was GPU limited. Adding more CPU power at that point won't have much of an effect.

Boris has a 8600GT which is pretty much the same as a 7600GT (despite the higher number) and is using a resolution very similar to mine, hence it's very likely he's GPU limited, especially since his CPU is significantly better. The only way to find out is to lower the AA level, and see if that helps.

Quote from wien :

Boris has a 8600GT which is pretty much the same as a 7600GT (despite the higher number) and is using a resolution very similar to mine, hence it's very likely he's GPU limited, especially since his CPU is significantly better. The only way to find out is to lower the AA level, and see if that helps.

from what he wrote hes only struggling when a lot of cars are around
the car models dont have nearly enough polys to cause a drop as large as the one you experience in lfs on grounds of gpu limitation (100+ => 30 in my case)

Quote from Shotglass :

from what he wrote hes only struggling when a lot of cars are around
the car models dont have nearly enough polys to cause a drop as large as the one you experience in lfs on grounds of gpu limitation (100+ => 30 in my case)

He also said it doesn't max out his CPU (or at least one of the cores), which points in the opposite direction.

But you're right that a full grid will shift the load from GPU limited to CPU limited in most cases. This is most likely because LFS doesn't use the API in a way that is efficient on modern hardware, so it spends too much time making API calls to keep up with the GPU. I'm certain LFS could see a massive improvement by just changing to a newer API and taking more care in batching to limit state changes. You don't even need multi threading to make that happen.

Quote from JTbo :

Nvidia drivers have one setting that optimizes driver for dualcore or something, haven't tested if that gives any boost.

According to nHancer this setting is for OpenGL only.

For comparison, the 8600GT is between a 7600GT and a 7900GS, however thanks to the 128-bit bus it gets closer to the 7600GT at higher resolutions / more AA.

Quote from Jakg :

According to nHancer this setting is for

For comparison, the 8600GT is between a 7600GT and a 7900GS, however thanks to the 128-bit bus it gets closer to the 7600GT at higher resolutions / more AA.

You getting old, sentence did not finish?

*slaps head*

Looooong day. Ill. Tired.


*collapses on floor*

Hmm, with full grid of RB4s, I got now 57fps at lowest, I had 8x AF and 16x AA, 1024x768, fps limited to 60, track was SO6 and I started at back of grid. See attachment, that is how CPU load was.

With full grid of FBMs I got around 40 without AA or AF.

Also I doubt a bit if my AA and AF settings are being used as at best effect seem to be very subtle