I recently bought and installed an MSI 660Ti Power Edition, and in the haze of building this completely new system simply installed the latest Nvidia GeForce drivers without really thinking.
Using GPU-Z, the clock speeds are all proper to the PE standard (they're not working at reference speeds), which is good. However when I go to MSI's website, they have drivers available for download that seem to be more specific to this graphics card. The problem is their version is 306.97 which was last updated in late October, whereas the GeForce drivers are from January of this year and are at version 310.90.
The question is: which should I be using for the best performance and compatibility with this card?
I've tried both with my MSI, and you'll def want to go with the new one. That's your best bet most of the time. Unless you were having issues with them, in which case dropping back to the manufacturer's last supported driver set would be my first move, but if it is working well and you have no issues stick with the latest and update regularly. There's always performance tweaks and newer game support added with updated drivers.