I've 2x 4GB Dual KHX1600-C9 [1.65v] on a MSI p67a-gd65. with a i5 2500k However, it seems to run only at 1333 Mhz.
Since I've only basic knowledge of all that clocking stuff, I wanted to make sure:
Can I simply raise the 667Mhz to 800 Mhz via BIOS? I'm unsure about the other paratmeters:
Should I leave them unchanged? Or to which values should I put them?
If the BIOS set your RAM parameters to 1333, that's what you have. The parameters are stored in the little SPD chip on each stick. What you more than likely have is DDR3-1333 RAM that has been tested and branded at the higher speed, usually at a higher voltage and more relaxed timings.
You will need to manually adjust all the settings and it should run at the higher speed.