I have just built a PC based on a Gigabyte DS4 motherboard running the F2 BIOS (installed when I got it) which I believe is the most recent release.
I got the system board and TwinX pack of 2 x PC6400 DDR2 for it from scan along with some other stuff but with both sticks of RAM in place the BIOS only sees 2032MB. With either one in the BIOS sees 1016MB. I have tried each of the sticks of RAM in each slot, on their own and in combinations.
Does this seem like fauly RAM or a motherboard issue as it's got me.
I ran memtest+ and it rtan the test on a detected 2032MB.