Fps drops while gaming?

[mo0121]

im using a xfx hd 5830. while playing mafia 2 or batman akham asylum the fps goes up to 80 then drops to 20 and then the game starts to lag?
ive updated the driver to ccc 11.10

 

[assassin123]

so on what resolution are you playing it

 

[mo0121]

1400x1050

 

[assassin123]

and also what is your vram of card

 

[mo0121]

1GB GDDR5

 

[assassin123]

do you run it first time on uoyr pc and other games work properly

 

[mo0121]

yes other games work smoothly like battlefield 2 etc

 

[assassin123]

then there must be something missing with your gpu and your gpu has'nt much power to run that games on that graphics

 

[mo0121]

so the problem is from my power supply?

CIT 750WATTS

 

[assassin123]

yeah man it is you didnt told me about you gpu

 

[mo0121]

i did tell you about my GPU...anyway so i need to change my power supply

 

[mo0121]

no, and also my ati card turns it off automactically