I think, for all practical reasons, the difference to the consumer is the performance. The 7200 drives show noticeable improvement in speed with ATA100 where the 5400 drives don't. ATA 66, small noticeable difference. _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com PCBUILD maintains hundreds of useful files for download visit our download web page at: http://freepctech.com/downloads.shtml