Add on:
If your computer supports up to eg: DDR2 3200
and you Have a DDR2 6000, it would be converted to running at a
speed of 3200.
like wise, DDR2 3200 , but u have a DDR2 1600, it would run too.
But at 1600.
But do note of the word behind the DDR. dont go buy ddr2 if you
can only use ddr