You will achieve similar results with qualified SCSI and ATA/IDE drives. The only noticeable performance difference might be a slight delay upon playback or recording in large sessions when using an ATA/IDE drive. SCSI is not a requirement for use with the Digi 001, however, if you are working in multiple studios an external SCSI drive allows easy portability to other Pro Tools Windows 98 SE systems. If you are thinking about purchasing a SCSI controller for playback and recording with the Digi 001, be advised that the ADAPTEC AVA -2906 SCSI controller card is the only supported model for Digi 001 Windows 98 SE Systems. We can not guarantee the performance of other SCSI controller cards. Review the Windows 98 SE Digi 001 compatibility available on our website document for more information: www.digidesign.com