After my 8800GTS broke I decided to buy an XFX HD5770 (mainly because I was having trouble finding stocks of equiv powered NVidia cards).
I removed the old NVidia drivers using Driver Sweeper, installed the new card and Catalyst 10.3 drivers.
MW2 (and all my other games) now perform so badly they are unplayable. So much lag it's like swimming in thick soup. The 8800 could run MW2 on max settings at 1680 res. The HD5770 can't even cope on low settings at 1024.
Re-installing MW2 had no effect.
I've checked the cards installation and power connector - all appear ok. CCC reports the card correctly (gpu clock at 400 idle and 875 in games). I've run the Windows optimisation and saw a jump in gfx from 5.5 to 7.2. Also tried various Cat drivers (10.1, .2, .3 and .4).
Full system spec:
CPU: Core2 Duo E6600 (stock speeds)
MB: Asus P5W DH Deluxe
Ram: 4 gig Corsair DDR2
PSU: Corsair HX620
Sound: Creative XFI Extreme
O/S: Win 7 64 bit
Have you measured the FPS? Install FRAPS to see what you are getting. I know you say it's stuttering and stuff, but I'd also be curious to see what FRAPS says your FPS is. For some, unplayable could mean below 60 fps (when it's around 45-50).
I also know that one time, I had a game perform SO poorly and it turned out it wasn't my GPU but it was the drivers for my onboard sound. I uninstalled the sound card drivers and reinstalled them and viola! Games performed flawlessly.
Make sure you didn't change anything else in your system. Also, check things like your disk controller drivers, etc.
I updated my bios, changed my onboard graphic to PCI-E (it was set to PCI? Maybe that's just because of the BIOS flash I did) I also saw an option in my bios for "CPU Temperature Throttling". I disabled it and everything seems to be relatively fine now. I still get a tiny bit of stuttering, but only every so often, and not 2 times a second as was the case before hand. (This is only tested in MW2 at the moment, as I formatted my drive and currently that is my only installed game)
As a side note, before I did the above, I had GPU-Z create a log file for my 5770, and then I ran the game, and wrote down the specific times events happened (IE. 11:45:12am: Game Started; 11:48:23am Stuttering begins). I then compared the events to the GPU-Z log file and found that the time that the stuttering began always matched up with a point that the GPU load managed to reach above 90%, and that at any point after that (durring stuttering) the GPU would no longer reach any where near 90% usage, and would only remain between 30%-60% usuage.
I'd like to say "Hope this helps", but I'm sure this is pretty specific to myself
I'll post again if the issue pops up in other games.
Well i hope you do not have problems from now on. I like my card(sapphire 5770 vapor-x) and i am happy to tell you that i play MW2 at 1920x1080 and max settings with no problem.
Crysis warhead gives me problems from time to time is like the video card disables the speed. It has 3 led's on the back. In 2d mode only one is lid up, in 3d the second one and the 3'rd is on but sometimes for breaf moments the 3'rd one goes off, and that is only in crysis warhead. The rest of the games are fine .