Stuttering/FPS slowdown after upgrading GPU!

[leviwilner]

So I upgraded to the: SAPPHIRE Radeon HD 6670 1GB 128-bit DDR3 from a GeForce 9800 GT 1GB 256-bit GDDR3

Now I'm noticing a stuttering/FPS slowdown in my games.
Here the deal:
I had played Skyrim (with the 9800) w/o problems on medium settings. Now if I play on medium or low settings Skyrim stutters!
I never measured with FRAPS on the 9800, but I have recently with the 6670 and am getting 17-30. I finished Skyrim on the 9800 and then it crapped out.

Sooo

I recently got Deus Ex: Human Revolution from STEAM. It's been stuttering since day 1, but not really lagging. Recently it's been getting on my nervs so I thought I'd try to find a solution. I've toyed with all the settings and it doesn't make a bit of difference. I've been all over the interwebz trying to find a fix and even changed the registry. I'll try flashing the MOBO to the latest BIOS tonight...

So, I'm having stutter issues with two games. What I'm wondering is if there is some kind of issue between my old CPU,MOBO,RAM combo and my new video card?

CPU: Intel Core2 Duo E8400 @ 3.00GHz
MOBO: ASUS P5Q SE
RAM: 8gb DDR2
GPU: SAPPHIRE Radeon HD 6670 1GB 128-bit DDR3
DRIVE: Cant recall 3gb/s 72000

Thanks ahead of time for your thoughts!

 

[Ballantin]

You moved from Nvidia to ATI, so I will first try to clean any unwanted drivers, with Driver Sweeper:

http://www.guru3d.com/content_page/guru3d_driver_sweeper.html

Then, download and install the latest Catalyst Drivers from AMD site.

Check also that the fan on the ATI card is working correctly, and there are no cables or something that stop it, or it is blocked/stuck.