There is only one drive manufacuter that supports ata133 and that is maxtor, but as other said, it is not any faster either. At the time that support for 48bit addressing startes (ie over 137gb) maxtor tied there support of it into there ata133 marketing which made it a little easier to find drive, or motherboads. But nowadays it does not matter, all board will support the 48bit addressing(over 137gb). but there still is no performance benift from it
Dahak