nforce2/865e and pc2100

[Kuato]

I was wondering if I have to buy new memory if I want to get an nforce2 ultra 400 for amd or 865 for intel processors. I currently use pc2100 and would like to hold off on updating the memory for a bit (but I need a new mb as mine just died). So I guess my question is, is ddr400 different from pc2100 other than speed, e.g. will the motherboard slow down so that the pc2100 is useable? I know there's a performance difference, but otherwise will I be ok using pc2100 in an nforce2 ultra board? Thanks in advance.

 

[mechBgon]

PC2100 can be used in an nForce2 board no problem (assuming it's not total junk or something). You'd want to use a processor with a 266MHz FSB, such as the 2400+ on down.