I have an Intel d915gev mobo which supports dual channel memory.

Currently I have 2 sticks of 256MB Hyper-x pc4300 in bank 1. My question is if I want to put in another pair of dual channel in bank 2 does that pair have to be 2x256 also or could I use 2x512 in bank 2?

I quess what I am trying to say is does all 4 sticks have to be the same size or am I ok as long as the size of the sticks in each bank match??

Thanks in advance.

Only the dual-channel banks have to be matching pairs, so you can install a matched pair of 256MB, 512MB or even 1GB sticks into the second channel