Hello, i have such problem with my new mobo. I have installed i7 930 and 6Gigs of RAM. First start was successful everything was correctly recognized, all amount of RAM seems like been used. But at the next day at the morning BIOS shows that only 2Gigs were installed. OS shows the same, but GPU-Z shows all amount of RAM, weird isn't ?
BIOS Update doesn't helps too. For recognizing all amount of memory, i must each time change RAM frequency, then mobo restarts and it recognize again 6Gigs.
More aboutasus memory trouble
Are you saving the ram profile? Is the memory running at the correct voltage? If the dram voltage isn't set correctly you'll have allsorts of issues.
Pardon, i mean CPU-Z.
About RAM Voltage, i have set it up to it's work voltage 1.5, then i left it by auto, same thing happens at the morning, 2Gigs only recognize by BIOS.