I want to throw in a 1 gb stick of RAM in My brothers Dell 2005 media edition xp. It has 2x512mb sticks (DDR2 400)my question is can add a stick that is DDR2 667?? or does the sticks have to be the same exact model??
Higher performance DDR2 DIMMs are compatible with lower performance DDR2 DIMMs; however, the higher performance module runs at the lower module's frequency. Using lower performing DDR2 memory in a system capable of higher performance results in the bus running at the rate of the lowest performance memory in use; however, in many systems this performance hit can be mitigated to a small extent by setting the timings of the memory to a lower latency setting.