i just got my first xeon x5675 and installed it on an asus rampage III gene with 12gb g.skill sniper.
It runs great so far, the only issue i have is, that im unable to set my ram speed to 1600mhz, no matter the voltage (1,5-1,66v) or settings.
The ram specs are DDR3-1866, CL9-10-9-28 (1,5v), but the pc wont boot unless the ram is set to 1333 or lower.
Im not sure if its the xeon restricting the frequency, since the official support is only up to 1333.
For the time being i managed to tighten the timings at 1333 to 6-7-6-18 (1,5v), but id really like to get it to 1600 if possible.
I also have a htpc with a xeon x5570 with 12gb g.skill ripjaws on an asus rampage III forumla, which runs fine at 1600 7-7-7-18 (1,5v), which makes me think, why it works with the x5570, but not with the x5675.
Also tried the ripjaws with the x5675 setup but same result as the sniper, the pc wont boot at 1600 frequency.
Cpu is clocked at 3,66ghz (22x/166blk/1,15v) for the time being.
If someone could give me a hint of what could be wrong, or an explanation, why it is the way it is, id be really grateful.