no, frothy... very different. your system bus is more like 100mhz... but "quad-pumped" or some rubbish. via's soon-to-be kt400, for example, will run on a 133mhz bus like most modern motherboards, but the memory controller will run at a swift 200mhz (for 400mhz/pc3200 ddr). this should give better performance than pc800 rambus and maybe even pc1066.
and MMF, be sure to go with ddr. sdr is it's predecessor and is becoming a thing of the past.