I really cannot be certain if it was a patch or drivers. But I do know that I haven't changed graphics drivers for a long time, and the official patches T & U ran pretty well as usual. I don't know where it started, but it might have been with a very early test patch, because in mid May, I had a OLFSL league race and it was very hard to drive in that from low frames. South City would usually drop my framerate only slightly, but this was plenty of frame loss... enough to lag my entire system and have unresponsive steering. I'm not sure when you started the test patches, but I'd say it was around May or June when I've had some bad fps experiences.
Since then I have tried different drivers dating all the way back from 2.4.96, all the way up to the recent 3.8.273 Catalyst version. I remember you reported that a few specific Catalyst versions had issues with LFS (something .x.11 and .12). When that was heard, I was using drivers that were only a few versions older, and they have worked great and given me the best performance ever in LFS. Any newer drivers... and I seem to get good performance in some areas, but with things like smoke and quite a few cars present, it just cannot sustain a decent FPS level.
I've had a fresh install of LFS S2U since July if I remember correctly, and drivers haven't helped the issue even then. I updated right away to a high U test patch (U15 I think?
), and then progressed up until U20 currently. I suppose I could try each version and see my results, but I need two things: 1) As many U-test-patches as possible to download, because I deleted all of the downloaded ones, & 2) lots of time
So I hope this is easy to figure out....