Vista - Lower FPS on better graphics card?

So i decieded to upgrade my Graphics Card

Upgraded from
VISONTEK ATI RADEON HD 4350
512 DDR2

To

VISONTEK ATI RADEON HD 4550
512DDR3

And WIth my old card i would get 50-60FPS but with the new one im only getting an average of 29-40FPS.

*LEFT 4 DEAD"

Highest Settings

DirectX Version is 10

Well if u have upgraded, ur graphics card must work better and it does there may be a fault in the graphics card or ur sensors.

Kidfork on this thread i gave you a link to a graphics card performace chart:

Vista forum links, please work

Youv replaced the 4350 with a 4550 which is in the same box. Performance will most likely be about the same. Some games may run slightly better but others may run slightly worse.

stew2, your link takes me to the main page of the forum

Not knowing ATI I couldn't tell you much but, the little I know, there are times when you tend to bottleneck your GPU with other resources when you upgrade.

Example: Your PSU is just right for the GPU, then you upgrade the GPU and now, the PSU is no longer able to move the GPU 100% so it lags a bit, hence, your drop on FPSs.

Again, I am not saying this is your problem

Cheers AstaLaVista iv updated the link.