Memory errors with two sticks or ram but not one?

3usrnam3

Honorable
Jun 10, 2013
20
0
10,520
I have two sticks of DDR3 1600 ram both with 11-11-11-28 timings. When I run each separate using windows memory diagnostic, I get no errors whatsoever. But if I run them together I get "hardware problems were detected" in windows memory diagnostic and BSOD in windows randomly. I have tested the two ram slots on my motherboard and both work fine. I don't know what's wrong, help!