Low FPS Issue. Please Help.

[ZzAsh92zZ]

Not sure if this is in the right place as its my first post but here's the question.
I have a low FPS when playing games. I get a solid 60 FPS on the menu screens.
But when starting the game, the loading screen again gets a solid 55-60 FPS but as soon as the game loads it goes to around 15 FPS and stays there. I don't know if this is causing the lag in game, not lag like jumpy but more input lag. I will move the mouse and about half a second to a second later the wheel (or whatever game I'm playing) will turn.

The main thing that has got to me is that I never had this problem before I had to re-installed windows (another problem nothing to do with gaming, now fixed) and I had no lag or low FPS.

I have tried updating the graphics driver, updating BIOS, reverting back to the drivers on the disk which I had installed before re-installing windows and another seems to be fixing the problem.

The computer is about 2 months old so there shouldnt be a problem with any of the hardware, unless I damaged something when installing 2 case fans.

My computer specs are:
AMD FX-8350 Eight Core CPU (4.00GHz/8MB CACHE/AM3+)
ASUS® SABERTOOTH 990FX R2.0 (DDR3, USB3.0, 6Gb/s, CrossFireX/Sli)
8GB KINGSTON HYPERX GENESIS DUAL-DDR3 1866MHz X.M.P(2 x 4GB KIT)
1GB AMD RADEON™ HD7750 - DVI,HDMI,VGA - DX® 11
1GB AMD RADEON™ HD7750 - DVI,HDMI,VGA - DX® 11
1GB AMD RADEON™ HD7750 - DVI,HDMI,VGA - DX® 11
120GB KINGSTON V+200 SSD, SATA 6 Gb (535MB/R, 460MB/W)
1TB 3.5" SATA-III 6GB/s HDD 7200RPM 32MB CACHE
CORSAIR 650W ENTHUSIAST SERIES™ TX650 V2-80 PLUS® BRONZE
Super Quiet 22dBA Triple Copper Heatpipe AMD CPU Cooler

Thanks in advance

 

[bumnut53]

I have to ask, did you enable crossfire again after reinstalling windows?

 

[ZzAsh92zZ]

No. I didn't have it enabled before re-installing as I use all 3 cards.

 

[ZzAsh92zZ]

Also to note, reducing the graphics to low fixes the problem. But it used to run it on ultra settings so I know the graphics card/my computer can run the game.