I run LFS usually with fps of 60. BUt when cars crash into each other, either infont of me or in the mirros the fps drop right down just foir a few seconds as the cars are crashing. When practicing in single player when all the AI cars pitted at the same time and all collided on pit entry was down to 4fps for a second or two. Any ideas what causing this.

I'm running 1280 x 1024 with everything on high, does 60 fps all day (even with a full grid) full screen and 99 when windowed, until cars crash.

Vista 64 premium
Asus P5N32-E SLI
DualCore Intel Core 2 Duo E6850, 3148 MHz (9 x 350)
4096 MB (DDR2-800 DDR2 SDRAM
NVIDIA GeForce 9800 GTX (512 MB)
Monitor Sony SDM-S94 DVI-D [19" LCD] (6240454)

G25 steering wheel.

Any help gratefully received.

Hmm, with those hardware specs your system should be quite capable of doing 60+ fps all day long regardless of what other cars are up to, except maybe something like a 30 car grid all piling in close up at turn 1, as there is an expected fps drop then for most of us.

However, i can't see why a crashing or spinning car should have any more effect on performance than just having a car driving quite close to you, as no matter what another car is doing, your graphics card still needs to draw it, weather its crashing or driving or whatever, unless the collision detection is causing something, but i have never heard of that issue before.

The only couple of things i can suggest to try is to drop down to a 1024x768 res and see if it helps, or hunt around for newer or updated drivers for your graphics card.

My 512mb ATI card has problems running resolutions as big as 1280x1024, especially with lots going on, but still playable, except form the turn 1 scenario i mentioned earlier, and dropping back to 1024x768 helped me, not majorly, but instead of having fps dive from say 65 to 10, it now only drops from 70 to 25, which is more driveable, although my nearly 8 year old pentium 4 CPU is more likely the cause of my poor performance with LFS.

As for drivers, i have tried three different sets and all gave varying results, some would give ok FPS in all games i like to play, some would give bad FPS in some games and good FPS in others, where as some were rubbish in anything, so my advice would be just hunt around and try a few sets of drivers and see which (if any) of them get rid of the problems.

Thanks for the input, I'm on the latest drivers from Nvidia, has been teh same for the last 3 or 4 updates. found this thread, sounds similar to my problem. ALways been a problem on this machine, even with different graphics cards, might be a vista 64 problem. This is the first machine I have had with V64.

http://www.lfsforum.net/showthread.php?t=59818

But they are talking about on board sound, I have a PCI sound card, All be it and very small one that came with the motherboard.

Perhaps I should add, I do get frame rate of say 30 rushing into turn 1 with a 30 car grid, but when the cars crash into each other its like a complete momentary glitch and frames are missed its very odd. Happen when the cars that crashed were a good way behind me and not even viable in the mirror too.