Because of the design limitations of the motherboard chips before the P3, there are a lot of them that only support up to 512, and have memory channel (bank) limitations. There used to be a lot of old PC100 double sided strips that took up two memory channels, when adding another double sided strip that took up two channels, it would only recognize half of the capacity, a problem that was common in the old days. Since your motherboard has only one slot, it should be fine whether you plug in single-sided or double-sided. But to be on the safe side, you might want to bring your board with you to get the RAM.