If One DDR2 RAM Modules of a Pair Goes Bad, Should I Replace the Pair?

Question

I have a self-built box with Gigabyte mobo that has 4 slots and accepts a max of 8Gb.

About 4 months ago, I added a pair of 2Gb DDR2 memory modules, and last week, one of the pair now fails boot-time memory test.

When I pull that module, the machine runs fine with the faulty one removed.

I want to go back to 8Gb; should I purchase another 2 x 2Gb pair or is it ok to simply purchase another DDR2 memory module of the same speed?

Is there any difference between a matched pair, and an unmatched pair (e.g. can I get a different brand?)

Answer 1

You do not need to replace the pair, just the memory that went bad. It's not like the EDO memory from the 90's where they had to be paired. Typically on motherboards like yours, you'll have Dual Channel memory which will see some speed increase when used in pairs. Functionality wise, you can mix and match memory and/or use any combination of slots. Keep in mind that memory will only function as it's slowest member so you will want to stick with the same speed if possible. However, it will technically work with different speeds. If you do plan on doing overclocking then you will probably want to go with the same memory. For the general user though, this is not a requirement.