I'm trying to get GA-P55-UD6 to work with 12 gigs of RAM. I'm using 2 Corsair TR3X6G1600C8D kits (3x2GB). This memory is listed in the supported memory list of the montherboard. But...
4 sticks - all works fine. BIOS and Windows report 8 gigs of RAM
5 sticks - it's weird - BIOS shows 4 gigs of RAM and Windows boost and shows the same
6 sticks - video doesn't initialize, speaker yells and POST code LCD on the mobo shows C1 (which quite predictably means detecting memory...)
Originally the mobo had P3 BIOS version. Upgraded to P4 - same stuff. Tried enabling and disabling XMP - same thing.
It doesn't seem to be tied to any particular memory stick. I've tried to rotated them and results are always the same. 4 sticks work fine. 5 detect as 4 gig rather than 10 and 6 don't work.
Has anyone successfully installed 12GB of RAM in this mobo.
My video is EVGA 280GTX and CPU is i7-860 if it matters. No overclocking whatsoever - everything runs on stock.
PSU is Seasonic 650W but I doubt that it is the problem.
I'm trying to find something definitive, but those DIMMs appear to be aimed at the 1366 platform, and are likely double-sided sticks... GB manual, page 16:
"When enabling Dual Channel mode with six memory modules, make sure that memory modules to be installed on the DDR3_3, DDR3_2,
DDR3_6, DDR3_5 sockets are all single-sided."
I took a better look at the memory compatibility list of the mobo - all 2GB modules there are DS. So this means that 8 gigs is the maximum unless I switch to 4GB modules which I'm not going to do for many reasons.
Oh, well. I guess this answers my question... I should have done more research before buying the thing...