If you have oc'd the first gig and install the 2nd value ram your system will run all the memory at the lower settings just as if you had 1 gig of pc3200 and then installed a 2nd gig of pc2700, the memory clock speeds and CS latency would be backward compliant with the pc2700 memory which, if value ram, is going to be 2-3-2-6-T1. That's how your memory timing then default
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EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.