AMD 7750 problem

[chill out]

My PC specification is :

Processor : AMD phenom X6 1045t
Ram : 8GB
Motherboard : Gigabyte GA-78LMT-S2P
Graphic Card : AMD 7750
PSU : Antec vp450p 450w

My problem is that even though most games runs at high FPS but there is a problem that annoys me and this problem is that in some games the screen freeze for a tiny little time (0.1 sec for example) but that tiny time makes the FPS drops to from 60FPS to 40FPS then returns to normal for a constant high FPS then after a little random time the same thing comes again making it unstable , little noise can be heard from the card but I don't know if it has something to do with the problem or it is the nature of the card but this noise disappears when the problem occurs in its tiny time

The games that do this thing the most are L.A Noire and Mafia II , my older card AMD 5670 didn't have this unstability problem in those games

Hope someone is familiar with the problem and have a solution for it , the card is nice except for this annoying problem and I hope there is a solution for it other than replacing it

 

[photonboy]

disable VSYNC and observe if the problem still exists.

When you drop below 60FPS, the graphics card attempt to resynch at 30FPS instead (FRAPS doesn't display the correctly).

If it doesn't happen with VSYNC disabled this is likely the issue. Two solutions:
1) Turn down the graphics quality slightly so it doesn't happen as often
2) apply AMD's version of Adaptive VSYNC (when/if they release it in a driver update. Only NVidia currently have this so you can Google it. Basically it turns VSYNC OFF if you drop below 60FPS so you'll get screen tearing but it won't resynch to 30FPS and cause a stutter).

 

[chill out]

disable VSYNC and observe if the problem still exists.

When you drop below 60FPS, the graphics card attempt to resynch at 30FPS instead (FRAPS doesn't display the correctly).

If it doesn't happen with VSYNC disabled this is likely the issue. Two solutions:
1) Turn down the graphics quality slightly so it doesn't happen as often
2) apply AMD's version of Adaptive VSYNC (when/if they release it in a driver update. Only NVidia currently have this so you can Google it. Basically it turns VSYNC OFF if you drop below 60FPS so you'll get screen tearing but it won't resynch to 30FPS and cause a stutter).

Thanks for your reply

I always have VSYNC off in all games I played , and it isn't a graphic quality either as for example I have L.A noire running with the same setting for both the old 5670 and the current 7750 , 5670 ran it with no "freezes" , it may have FPS drop and rise but it didn't "freeze" even for a tiny time , on the other side 7750 runs it at constant and high FPS but when the problem occurs it "freeze" for a tiny time and then it resume then after a random little time it , the little noise that the 7750 fan does is disappeared when that freeze problem happens

Shall I upload a video describing the problem ?

 

[chill out]

I begin to think that it is a Processor problem and more specially a fan problem rather than a graphics card problem , I replaced the 7750 with 7850 and the exact problem happened

So is there any solution to this by changing clock values or any other solution other than replacing the fan ?