UltraSCSI is ultrasensible


Tip
Talk to disk drive makers, and you'll think the solution to all our problems is a new standard called Fibre Channel. But it's probably not a solution for you -- yet.
Despite its name, Fibre Channel uses ordinary copper connections to transfer data at 100Mbit/sec and faster. It's one of four connection schemes allowed under the SCSI-3 standard, another being the SCSI Parallel Interface -- the SCSI we know today.
You can buy Fibre Channel drives today. Don't. You'll need a new drive plus a new host adaptor -- and probably a new credit card -- to take advantage of its virtues.
Fortunately, there's a good interim alternative: UltraSCSI. UltraSCSI is familiar Fast SCSI-2 taken one step further. Where Fast SCSI-2 doubles the original SCSI-1 data rate, pushing the bus speed from 5 to 10MHz, UltraSCSI doubles it once again, to 20MHz.
UltraSCSI speed is independent of bus width, so it delivers three performance levels. With 8-bit connections, it delivers a peak transfer rate of 20Mbit/sec. With 16-bit Wide UltraSCSI (probably the most common form), you get 40Mbit/sec. And with a 32-bit Wide connection, you can expect 80Mbit/sec -- a rate that will give PCI adaptors a run for their money.
UltraSCSI is backward compatible with Fast SCSI-2 and costs drive makers little more to make. And the bus clock of UltraSCSI is independent of file structures, partitioning and even low-level disk formats. You can plug an UltraSCSI drive into your current SCSI host adaptor (with the right cable), and get all the speed your host adaptor can deliver. If you later buy an UltraSCSI host adaptor or move your hard disk to another PC, you gain more speed without monkeying with software, files or other such nonsense. Put UltraSCSI on your shopping list for your next hard disk.

Category: Hardware
Issue: Feb 1997
Pages: 175

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