Hi! As I´ve been able to read almost everywhere in the net, many people experience sudden FPS loss with no apparent reason. It´s happened to me. For months it ran smooth as silk at high settings despite my rather humble rig, and suddenly, a couple of months ago, it started to get choppy. At first, I thought it was software related. I uninstalled the game a few times, tried installing in a new HDD, to no avail. So, I looked at hardware related problems, tweaking my GPU, etc...to no avail. Still the same, got average 20 FPS on the monaco banchmark. For many weeks, I read all F12011 forums, and tried all possible solutions, but nothing, and my despair increased considerably. But yesterday, I came to a thread of a guy with a system pretty much the same as mine (Q6600 @ 2.4GHZ, HD5870, WinXP, 4GB RAM) who said his problem was as simple as a dirty PCI sock and dusty GPU vent and air intakes... This morning, I opened my rig, got the GPU out, and I can tell you it was dirty... I cleaned everything deeply, and booted the system again. First thing I noticed was my GPU idle temps going from 60-62º to 50º. Great! I started F12011, made a new monaco benchmark and voilà!! My average FPS on the benchmark went from low 20s to 30s! with a minimum of 23 while before I got a minimum of 13! And GPU temps at full didn´t get past 69º while before it could easily go to the 80sº. So, if any of you suffer from this, just try to clean everything up. It´s well worth a try, as it may help a lot as it did for me.