refresher on the various flavors of SCSI and their relevance to my 9600.
U didn't say which 9600, so...
http://www.everymac.com/systems/apple/powermac/stats/powermac_9600_200.html
and
http://docs.info.apple.com/article.html?artnum=51132
ïWhat is the difference between SCSI 1, 2, and 3?
See below for full SCSI listing. Essentially, the higher the number the faster and more expensive the drive.
ïWhat is narrow, wide, fast, fast wide, ultra, etc?
Narrow is parallel 8-bit. Wide is parallel 16-bit. A Wide interface is twice as fast as a Narrow, given the same clock speed, because it moves twice the amount of data at one time.
Fast is twice the speed of the previous Narrow version.
Fast Wide is double the speed and wide, so it's 4x the Narrow.
Ultra is the name they used when they invented the thing that came after FW. Has nothing to do with Ultra Lord, but there are lamas involved.
ïWhat drives can I plug and play with the 9600 bus?
Your PowerMac has *TWO* separate/independant SCSI busses. The external bus is SCSI-1. The internal bus is SCSI-2 Fast.
ïWhat drives need an upgraded SCSI card?
Onto your built-in buses, you can put any SCSI-1 or SCSI-2 drive. You can also use some SCSI-3 drives - but they'll require an adapter. In general, if the drive is LVD (low voltage differiental) you can use it. If the drive is HVD (high voltage differiental, or just D) stay away!
You don't "need" to add a SCSI card unless you want to use the later model SCSI-3 versions and "must" have their additional throughput.
All internal drives are on the same bus and have the same transfer rate, no?
No. It depends on the capability of the drive and what combination you've used. In general, the bus will operate at the speed of the slowest active drive's interface. But that doesn't take into account spindle speeds. eg: A 3" 7200rpm SCSI-2 drive will always clobber a 3" 5400rpm SCSI-3 drive. :)
Also, how might I find out the rotational speeds of my various drives?
Look up their model numbers on the vendor web sites.
Here's the full SCSI listing...
SCSI-1
8-bit, parallel, 10-MHz, 5MB/sec sustained.
Uses 50 pin connector, but only uses 25 of the lines.
Requires passive terminations.SCSI-2 Fast Narrow
8-bit, parallel, 10-MHz, 10MB/sec sustained.
Requires active terminations (ditto for all other SCSI 2/3).SCSI-2 Fast Wide
16-bit, parallel, 10-MHz, 20MB/sec sustained, 15 devices max.SCSI-3 / Wide Ultra SCSI
Essentially SCSI-2 Fast/Wide, but at 20-MHz and 40 MB/sec.SCSI-3 / Fiber Channel
Serial; 127 hot-pluggable devices per bus; 100 MB/sec.
Uses fiber optic cables up to 10km long, or copper wire cabling up to 100m.SCSI-3 / Serial Storage Architecture (SSA)
From IBM. No support in Mac world.
127 hot-pluggable devices per bus; 80 MB/sec.SCSI-3 Wide Ultra2
80 MB/sec, 15 devices max.SCSI-3 Wide Ultra3
160 MB/sec, 15 devices max.SCSI-3 / FireWire (aka IEEE 1394; Sony's iLink)
Serial; 63 hot-pluggable devices per bus; 100 Mbps to 3.2 Gbps.
Apple's initial implementations are 400 and 800 Mbps (40 and 80 MB/sec).
Uses thin 9-pin cables, which carry up to 60 watts.And one final interface -- SATA. IDE is history, finally! This is the present and future. Apple has already put it in the Power Mac G5:
Serial ATA -- SATA -- Serial Advanced Technology Attachment
0.7 volts, 7 pin. Transmits each 8 bit byte as 10 bit character.
One device per iface, ie point-to-point only
Initial vers is 150 MB/sec. Future vers will be 300 and 600 MB/sec.The above is obviously missing details. If anyone wants to supply them, I'll add...
HTH, - Dan.
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