Why there are jerks during gameplay (Athlon 6000+) ?

[gamesutaki]

My pc configuration is

Amd Athlon x2 6000+
3gb DDR2 Ram
Ati Radeon HD 3650
Windows xp sp3

I am getting acceptable framerate of about 35 fps in games like crysis , callof duty 4 etc at high settings
But I am facing sudden jerks during gameplay . I am facing this problem not only in next-gen games but also
in very old games like "no one lives forever" So in short in all 3d applications . So system requirements is not at all problem .
Can anybody suggest what is causing this problem

 

[nish_higher]

drivers ?
install latest ones and then check

 

[comp@ddict]

Psu Psu?????

 

[arijit_2404]

PSU can be a distant reason.
Recently I was getting many jerks in my 8600GT w/ Athlon X2 3600+ in many games including old Half Life2 etc.

Few days later PSU and mobo broke.

Got a new one now with best quality PSU!

 

[comp@ddict]

Luks like the guy wid the problem doesn't care since he's not posted anymore