A moderately fast 2 GB or 4 GB drive will usually be adequate. The best way to configure a PCI Power Mac with a Fast SCSI-2 port is by adding a SCSI board, such as those from FWB and Atto. If you're using an array, you can connect all the drives to a single SCSI port. If you buy a PCI board with dual SCSI ports, you can connect half the drives to each port. This arrangement provides the highest data-transfer rates.
Most boards also offer analog component input and output connections as an option.
The component option on Data Translation's PCI Vincent board is an example of the latter. CD-quality digital audio is transferred along with the digital video data. FireWire ports make nonlinear editing systems' AV boards obsolete, because they eliminate the need to convert captured audio and video from analog to digital. The X1000's video signal exists fully in the digital domain. These video cameras' S-video connections provide the full recorded chroma bandwidth.