bought 2 lots of 2 x 2gb ocz pc8000 reaperx,
can't boot with more than 2 installed.
relaxed timings to 666 18 tryed 2.2v running at basic 800.
no go
2 works great and can get it to boot with 2 old 1gb sticks in as well total of 6gb but performance was poor as they're only pc6400.
tested each stick individually and all are ok.

am running vista ultimate 64bit a resource hungry bugger.
trying to get crysis running as it should and heard the more ram the better.

just using 2 sticks at momnet and its working great at 555 15 at 900 with cpu oc'd to 3350 (qx6850) fsb 1350 x10.
just want to get all the 8gb in there...

Most motherboards don't perform very well when all slots are filled. It could also be that your PSU cannot power the extra RAM