Why is new graphics card overheating?

[tmorales509]

I bought my computer from best buy. It is a compaq presario cq5300y. The only thing i upgraded was the memory to 4gb. I decided to upgrade my video card and got a radeon hd 4850. Anyways after installing i was able to play a game for about 1 minute when the fan kicked on high gear. I touched the card and it was really hot, about 10 minutes later my monitor turns off and the card just has a red light, i guess a overheat indicator. I bought a cooler master 460watt power supply since i read that my stock ps may not be supplying sufficient power(250watts) and the problem keeps going.

As of right now, doing nothing but browsing the card is 88C, after playing diablo 3 for literally 1 minute the card jumped to 98C and the fans started slowly getting faster. So whats the problem? I dont want to just go down a list of things to try since i've already spent more than id like. If anyone knows exactly or has a good idea of what it can be please help. Thank you!

 

[setishock]

Not enough airflow in the case. Prebuilts are bad for not having good airflow.
To have a high end graphics card you have to have a solid power supply and lots of air movement.
Need a fan in the front of the case pulling air in and a fan on the back pulling air out.

 

[tmorales509]

Ok thanks, i dont think fans are that much? I guess i can go pick a couple up.

 

[dale]

Forewarning: it's a combination of case design and fans rather than just an extra fan or two