Well first off, you can't run memory at different speeds. And seeings that those two sticks of RAM run at different speeds, you won't have much luck here. You might be able to OC one stick to match the other, but not if it's "****ty".
The option on my Phoenix BIOS is in 'Advanced Chipset Features', and then 'DRAM Configuration'. Put the speed on 'Manual' and then you can tweak all the timings and clocks.
EDIT: Unfortunately RAM does not have a temperature sensor, so you can't check the temps.
Intel Q9400 | Gigabyte EP45-UD3P | G.Skill 2x2GB DDR2 1000 | XFX HD5870
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