I've been having problems with frame rate dips when playing games - I've monitored my FPS on L4D1/2 and Alien Storm and it drops for the usual 60fps to around 20, sometimes down to the low teens. It doesn't seem to be tied into what's going on on screen, although when it dips and then lots of stuff happens on screen, that's when it dips really low.
I haven't noticed any changes when using Windows 7 at other times, and when I check task manager/resource monitor, I'm not seeing any spikes in CPU or RAM usage, when I've got say chrome, outlook and steam running. The biggest Windows resource running is an svchost that is about 60-70MB, and it looks like superfetch is the main user of RAM here. CPU use is pretty much normal.
I used Real Temp to check the heat when playing L4d2, and it said the max temp was around 75 (I think), so don't think it can be a temp problem. My PC is pretty near a radiator, but the air coming out of the fan is cool and the case itself is cool and the area/air around it isn't hot at all. I have a 350w PSU, and I think the 5670 recommends a 400w supply, but have been told that shouldn't be an issue.
I've uninstalled (through device manager, not removed it etc) my HD5670 and reinstalled it, uninstalled the Catalyst Control Centre and it makes no difference. The only things I can think have happened to the PC since I last played it a week ago (and it was working fine then) has been some installation of some windows updates on 9/11/11 and I played Alien Breed 2 for the first time and I think that may have done something to the Direct X, as some games do when they first boot. I uninstalled the updates from 9/11/11 and that made no difference either!
If anybody can can suggest any possible solutions, I'll be very grateful!
Thanks in advance!