XFX ATI Radeon 5770 laggy

[Aardvark55]

I recently bought an XFX ATI Radeon HD 5770 card to replace my very old NVidia card. After installing the card and the latest drivers I noticed that it was a bit laggy. I started up an older game (Call of Duty: Modern Warfare 2) which ran fine with my old card and it was also having laggy spikes, especially when starting up a new mission.

I updated my BIOS and it didn't help. I also made sure that all of the old NVidia drivers were completely removed.

Any other suggestions?

Here are my specs:

Intel Core 2 CPU 6600 @ 2.4GHz
2GB RAM
Windows 7, 64 bit
Gigabyte GA-965P-DS3 motherboard

If there's anything else that will help, please ask.

Thanks!

 

[Aardvark55]

I realized that I left out some potentially important information... my power supply is an ATX12V 380W. I've seen a lot of posts here and elsewhere that the Radeon card has high power requirements. Could this cause the laggy behavior that I'm seeing?

Thanks!

 

[Aardvark55]

Another update... I replaced my power supply with a 600W power supply and it didn't help.