I believe that if it seems fast, then it is fast. I test stuff and report it just so it can be found on the Web, (not to make my phallus size seem larger). However, a U320 15K rotation speed HDD will get 36 MB/s out of a CSPPC/CS MK 3. Those numbers don't mean much in real world applications. I wanted the FastATA 4000 to backup partitions to a CF card faster than the standard A4000T IDE.