New Build w/Gigabyte GA-P55-UD4P - BIOS v. F3
8 GB of Corsair DDR3 (4x2GB) 1600
750 watt Corsair HX PSU
EVGA GTX 275
i7 860 CPU
2 x WD Caviar Black 1TB HDD
OCZ Vertez SSD - System Drive
On first boot (cold) BIOS shows all 4 DIMM slots as active and Win7 shows 8 GB or RAMM. After re-boot BIOS shows all 4 slots as occupied but only slots 1 and 2 as "active" w/total RAM @ 4 GB, windows reports 8 GB total and 4 GB as "usable"