Posted 24 February 2010 - 11:36 AM
I've been upgrading a couple of PC's over the last week and am somewhat puzzled by the results. Both systems use DDR2 PC-4200 RAM. Both have two slots and can run a max of 2GBs. Both had 512mb already - one 256x2 and the other one stick of 512mb with an open slot. I replaced one of the 256mb sticks with a PC-5300 1GB stick. The PC now recognizes both sticks and shows a total of 1.18GB available. The other PC, however, will only recognize the new stick when I install it in the open slot. I tried the 256mb stick from the other PC and it ran with the 512mb stick and the PC recognized both. I thought the higher speed stick might be the issue, so I returned it and got a PC-4200 stick. After installing it, I got the same results as with the PC-5300 stick. When I go into setup, BIOS only recognizes one slot as having installed memory. Why would it work with the smaller stick, but not with the larger? Anyone know of any adjustments I can make?