I've recently assembled a PC with two different brands of memory with identical timings (9-9-9-24) and speed (1333 MHz). My motherboard, an Asus P8Z68-V, has independent memory channels, leading me to believe that identical timings shouldn't even be an issue. However, my system is very unstable. Sometimes it fails to POST after hibernating. Other times it crashes in applications under Ubuntu 12.04. Ubuntu frequently reports errors related to the video card, which is internal to the Intel 3770 CPU. For example, Firefox just reported
Notes: OpenGL: Tungsten Graphics, Inc -- Mesa DRI Intel(R) Ivybridge Desktop -- 3.0 Mesa 8.0.2 -- texture_from_pixmap
It worked reliably with only one pair and brand of memory. The problem started one week after I installed the second pair and brand. (For the first week it was fine.) Interestingly, this is the second pair of the second brand I've been through--the first pair had a faulty stick.
I'm not sure whether the problem is with the memory itself, an incompatibility, the motherboard's hardware, its configuration, or even the CPU. I have not overclocked anything. I've run memory tests all night without finding a single error.
What steps should I follow to troubleshoot the error?
edit: The BIOS was misconfigured for some reason. I fixed it and it worked fine for the rest of the day. Then I hibernated for the night and it failed to POST in the morning. I had to remove and re-insert a stick (I chose one of the new ones) to get it to work. Could a software bug be responsible for this or does it necessarily indicate that something is still wrong with the hardware?