RDRAM has worse seek times than SDRAM, and will actually hinder a PIII's performance. The only reason Intel started making RDRAM boards for PIII's was to get the world used to it by the time the PIV's came out. Do not use RDRAM with a PIII, it will slow the system down over SDRAM, the PIII can't take advantage of the bandwidth and the seek times are a deal-breaker.