Well I run everything pretty much ma.... Oh, sorry!
To the point: I find that playing with minimum sleep can help on a single core cpu. Finding the balance between background tasks and LFS. What it should be depends on your system.
On a multicore system, limiting frames is an option I find appealing, but I have never ben able to get that particular setting to work as expected. In rFactor I have limited my fps to 40 and it never ever drop below. That's awesome, and I'd like the same for LFS. If I set the limiter to 40 fps, I get a very 'jerky' game, where framerate is anything but smooth. Even though my system is capable of putting out 100+ fps most of the time, and very seldom drop into the 60s, locking at 40 let me see anything from 20 to 80fps, but with sudden changes in framerate, which is even worse than low fps.
I have experimented a bit, trying to find the bottleneck, and it's definetly CPU and/or RAM. Crancking gfx settings as high as they would go and even using two screens hadly dent the fps*, but put a few AI in the mix, and even the most high-end system is brought to it's knees. No wonder most developers fudge the AI....
One can only hope I get the fps limiter working someday, as a stable framerate is preferred over high framerate any day (as long as the stable fps is acceptable, of course. No good having stable 25fps.)
*
Amd Athlon 64X2 4200+ @ 2675
Abit KN8
XFX 7800GTX
1Gb twinMOS PC3200
3200x1200, 8AA, 16AF, high quality in drivers, all maxed ingame. Online 70+fps.
800x600, 0AA, 0AF, normal quality in drivers, all but HVS turned off, back of the grid, 12 AI, 25fps going into turn 1 on Blackwood.