Memory replacement question

[Catamer]

you can't or at least shouldn't mix and match. the memory should be the same speed and preferable the same manufacturer and/or model.

the 10600 are faster but it may not be night & day faster, so if it doesn't cost too much go with the faster.
I personally found that corsair dominator's using an XMP profile worked better than the OCZ ... just my personal experience, i'm sure someone out there might prefer OCZ over corsair.

[Sam DeathWalker]

Should go with 6 X 2G moduals.

You can get the slower/cheaper ones (but they should all be the same); ram is never the bottleneck in multiboxing.

PC-8500 is 1066 ram.

http://en.wikipedia.org/wiki/DDR3_SDRAM

Just get the slower ram the PC-8500 or 1066 ram you don't need the 1333 ram, and if you mix you will just run at the slower ram anyways.

Best check if 4 rams are ok for your board, just a long shot. Seems 6 is better with i7 iirc.

If you have 4 I would order 3 more like what you have (same part number), and have a spare so you can swap out untill you find the bad one.