Awmont wrote in message <1998032414215700.JAA05834@ladder01.news.aol.com>...

>For a conventional video capture input card, the conventional advise is to get
>a wide Ultra SCSI controller card and a wide Ultra SCSI hard drive. That makes
>sense to me, because you need fast drives (and presumably a fast system bus) in
>order to avoid dropping frames.
>But why would I need a wide Ultra SCSI controller and wide Ultra SCSI drives if
>I am getting my data from a digital camera through a Firewire card?
>Isn't the sustained data rate of a Firewire card going to be significantly less
>than a conventional video capture card? (Because it is already compressed in
>the camera.)
>I understand that digital video over Firewire is something like 3.6 to 3.8
>MB/sec, less than the 5 MB/sec that most cheaper narrow SCSI-2 hard drives are
>capable of. (Some SCSI-2 drives are even a bit faster than that.)
>I own a PowerMac 8500 upgraded to 233 MHz 604e, and the internal SCSI bus is a
>fast narrow bus, which maxes out just under 10 MB/sec. As long as a I buy a
>narrow SCSI-2 drive, shouldn't that be more than fast enough for use with a
>FireWire card? That would be a lot less expensive than buying an Ultra wide
>SCSI drive and a new controller.
>Am I missing something here?

I don't think so...;-) I got scared about the Spark incompatibility problems,
and after seeing the VERY short list of HD's that were OK'd to work with
the Spark, I went conservative-on-a-budget and got a pair of IBM 9-gig SCSI
drives at onsale.com for a good price (the specs looked right, but I worried
about them...), and plunked down the $300 for the Adaptec 2940 UW (I built the
rest of the PC computer to be likely to work with the Spark). The whole thing
worked fine (after some software update downloads...). I then replaced my "C"
drive with the UDMA IBM Deskstar 8 (8.4-gigs). Guess what? I can capture DV
video even to that IDE "C" drive just fine... (and the fast SCSI-drive heat
problem is non-existant). BTW, I think for DV capture/playback, the ONE
important HD spec (assuming no thermal recalibrations problems, etc.) is the
*MINIMUM* SUSTAINED DATA TRANSFER RATE (5.7Mb/sec with the Deskstar 8).
If that is high enough with your drive, you should be OK, as far as I know...

--
David Ruether
http://www.fcinet.com/ruether
ruether@fcinet.com