I have a Gigabyte Z68X-UD3H-B3 rev 1.3 motherboard. For RAM I have 2 x Patriot PSD34G13332 PC3-106000 DIMMs 4Gb running at 9-9-9-24 @ 1.5V. I was running just fine for over half a year when my computer became wildly unstable. It started BSODing in Windows 7 64bit, and apps would crash regularly. The hardware is not overclocked and now I am running it from the fail-safe BIOS settings.
It took me a while (full system reinstall, which failed at first) but finally I fired up Memtest86. Immediately it became apparent that one of my 2 DIMMs is bad. When testing with both, a flurry of errors appears. When testing them individually, one passed all the tests while the other lit up my screen in red.
I went to the store and swapped on of these two DIMMs for an identical one. I put in in the PC and fired it up. The system ran alright, but after a while it BSODed again. I ran Memtest86 and this time, intermittently, in test #6, #7, and #8 it showed a few errors in the 4950MB - 5050MB range. I swapped the DIMMS in their slots and the same issue appeared in the same general memory range. I tried putting the DIMMs in different slots and the issues continued. However, when I run Memtest86 with only 1 DIMM installed (4GB total RAM) all tests pass.
This leads me to believe that now I have two good DIMMs on hand but something is wrong with the motherboard. I am having trouble coming up with what though. I would like to run with 8Gb of RAM, but the mobo does not want to cooperate (reliably).
Can anyone diagnose this issue from the description I have provided, and possibly suggest either a solution or a way of figuring out what is the matter?