User guide

Will LVD drives work with my ATTO SCSI HBA?
Can I format my drives as a RAID to increase performance?
How do I configure a striped set of drives for AV OptionXL
What is a SCSI ID?
Can I put a wide to narrow adapter on my wide drive and install it in my old narrow enclosure?
How can I mix different SCSI types on the same SCSI HBA?
Can I still use FWB 3.02 to initialize my drives in OS 9.
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So if the maximum throughput is only 8.8 MB/sec (for TDM MIX), do you really need a 100 MB/sec
(ATA/100) disk drive? What about SCSI - do you really need an LVD Ultra/160 disk controller and drive?
The answer - no.
It turns out that super duper disk I/O throughput is not really a major factor (after a point) for Pro Tools. In fact,
you may actually experience more problems and unwanted side effects from ATA/100 or Ultra/160 SCSI disk
subsystems. What are these side effects? Some ATA/100 or high-speed SCSI controllers have drivers that hog too
much CPU bandwidth or PCI bandwidth (holding off interrupts for too long, or dominating the PCI bus). When this
happens, you may experience -9092, -9093, -9128, or -6042 errors when using Pro Tools.
This is why we recommend that users of SCSI systems "throttle back" their SCSI controller (like via the SCSI BIOS
with Adaptec controllers) to 20 MB/sec instead of 40, 80, or 160 MB/sec (the most common defaults). Higher values
may cause the SCSI PCI card to generate too much PCI traffic, and you don't really need that much disk I/O
bandwidth anyway (as explained above). We recommend 20 MB/sec for SCSI systems to give a bit of "headroom"
when there is disk fragmentation and/or a lot of dense edits within the Pro Tools session.
ATA/100 systems can work, but we've seen evidence of poorly written drivers that don't work as well as ATA/66 or
ATA/33 systems. For instance, it's known that the currently shipping drivers from VIA for the VIA 686B South
Bridge (on many new motherboards) have performance problems under Windows 2000. Fortunately, the problems
don't exist under Windows 98SE or Windows NT, so Pro Tools users are currently immune to this specific problem.
However, we have seen reports of bad performance with ATA/100 drivers even under Windows 98 (different but
related performance issues). Over time these driver issues will probably be resolved, but it just goes to show that
"faster" is not always better.
From Kenn LeGault's Digidesign User Conference post on 1.22.2001:
http://duc.digidesign.com/showflat.php?&Number=333578
SCSI Basics Index | All FAQ Index
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What drives should I use with Pro Tools and my ATTO dual channel SCSI Host Bus Adapter (HBA)?
The ATTO EPCI-DC SCSI HBA is an ultra wide SCSI card. Therefore, all wide drives will work with the ATTO EPCI-DC
HBA. Narrow SCSI drives will also work, if used, they should be the last devices of a wide SCSI bus. Note: A
terminating adapter should be used between the last wide device and the first narrow device. The adapter must
terminate the unused signal lines of the wide bus.
Low Voltage Differential drives are wide drives that are compatible with single ended Ultra HBAs like the EPCI-DC.
However, you will have to keep total cable length on each bus to less than three meters, since the EPCI-DC is a
single ended HBA.