ATA Disk Drives
There are two kinds of ATA disks:
 Parallel (Ultra) ATA disks: These are found in Power Mac G4 computers.
 Serial ATA disks: These come with Power Mac G5 computers.
ATA disks do not offer as high a level of performance as LVD or Ultra160 SCSI disks. If
you plan to use Ultra ATA disks, make sure that:
 The sustained transfer speed is 8 MB/sec. or faster
 The average seek time is below 9 ms
 The spindle speed is at least 5400 rpm, although 7200 rpm is better
Parallel (Ultra) ATA Disks
Many editors use parallel ATA (PATA) disks (also called Ultra DMA, Ultra EIDE, and
ATA-33/66/100/133) with DV equipment. Parallel ATA disks are disks that you install
internally. Because imported DV material has a fixed data rate of approximately
3.6 MB/sec., high-performance parallel ATA disks typically can capture and output these
streams without difficulty. The numbers following the ATA designation indicate the
maximum data transfer rate possible for the ATA interface, not the disk drive itself. For
example, an ATA-100 interface can theoretically handle 100 MB/sec., but most disk
drives do not spin fast enough to reach this limit.
Parallel ATA disks use 40- or 80-pin–wide ribbon cables to transfer multiple bits of data
simultaneously (in parallel), they have a cable length limit of 18 inches, and they require
5 volts of power. Depending on your computer, there may be one or more parallel ATA
(or IDE) controller chips on the motherboard. Each parallel ATA channel on a computer
motherboard supports two channels, so you can connect two disk drives. However,
when both disk drives are connected, they must share the data bandwidth of the
connection, so the data rate can potentially be reduced.
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Part III
Setting Up Your Editing System
Serial ATA Disks
Serial ATA (SATA) disks are newer than parallel ATA disk drives. The disk drive
mechanisms may be similar, but the interface is significantly different. The serial ATA
interface has the following characteristics:
 Serial data transfer (one bit at a time)
 150 MB/sec. theoretical data throughput limit
 7-pin data connection, with cable limit of 1 meter
 Operates with 250 mV
 Only one disk drive allowed per serial ATA controller chip on a computer
motherboard, so disk drives do not have to share data bandwidth