I have a PC that I built about 5 years ago that uses PC2700 DDR RAM memory. What would happen if I purchased 1.0 gig of the newest spec RAM, say a DDR2 667MHz strip with the same pin configuration as the old RAM and put it in the old PC? Would it just operate at the slower buss speed or refuse to operate altogether? I know - "Why would you do that?" I just want to boost my current (old) system with some RAM that I could potentially use when I inevitably have to build a new PC.