I still feel I need to remind you guys that quads add a ton of load to NB chipsets, specially when the CPU is overclocked. I found using 1 dimm was able to pass tests but the load of 2 dimms and the quad with 400fsb pushed some chipsets to hard...and I test a few boards remember

All these huge clocks on DDr3 are with 2GB kits and E8500's, makes you wonder why

790i is better than X48 with 4 and 8GB though, so there is hope