I recently shifted my house and during the moving process I decided to chuck the 22" monitor that I had for the time being and connect my PC to a 40" LED TV I have in my living room. All worked well and surprisingly my HD4850 GFX even handled full HD gaming at the regular settings that I used to play without any sort of lag whatsoever. However, after some time I set my room up and shifted the PC to my room and connected it as usual to my 3 yr old Samsung 22" LCD. I booted the system up and there was lag everywhere. From browsing through folders to navigating through tabs everywhere there was lag. The performance monitor on my G15 showed the cpu usage hovering around 30-40% even at idle. Then I tried playing F1 2011 just to check if this issue persisted even with games and I was in for a shock. There was massive lag. Reducing the settings didn't help either. Tested with COD MW2, L.A.Noire and Hot Pursuit 2010 as well. I am simply fed up.
The following solutions were tried out by me,
1) Clean the entire cabinet up. Take connections apart and put everything back in its place very carefully. Cross checked thrice and nothing is improperly connected / left unconnected.
2) Removed ATI drivers. Booted into safe mode. Used driversweeper and reinstalled all ATI drivers but to no avail.
3) Cleaning up all the fans of the PC and making sure they spin correctly without any resistance whatsoever.
4) Taken RAM sticks. Wiped and switched slots. (I don't know how this would help but just wanted to give it all a go)
But all this has been of no use and still the issue persists. I would be grateful if you guys could help me out with this.
My configuration is,
The refresh rate is 60Hz. That isn't a problem for the lag I presume since refresh rate can in no way even remotely affect my CPU usage.
I don't think the GPU has gone kaput either. According to GPU-Z my HD4850 idles @ 500MHz core clock & 750MHz memory clock at idle. Under load it goes to 625MHz core and 990MHz memory clock as per Catalyst Control Center settings. Is there any other possible reason for this problem ?
Can power supply cause this problem ?
EDIT: Running an entire system scan including a scan of operating memory to see if its a virus causing the issue. But I am pretty sure it isn't the problem.