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From: FelineGrace@cup.portal.com (Dana B Bourgeois)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Seagate Drives
Message-ID: <42601@cup.portal.com>
Date: 23 May 91 05:42:31 GMT
References: <9105152355.AA05412@thunder.LakeheadU.Ca>
  <42421@cup.portal.com> <21748@cbmvax.commodore.com>
Organization: The Portal System (TM)
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Dave, thanks for all the comments on my questions about sustained SCSI
transfer rates.

First, I am talking about a SPARC 2 so I don't know if that is considered
a low-cost workstation or not.  You didn't mention it when listing a few
models so I'd guess not.  SUN prints numbers like 2-3 MB/s for it and
claims it is SCSI 2.  (oops, they claim 1.8 MB/s, 3 MB/s synchronous).

Second, after I posted my qustions I received the latest Seagate catalog.
They have some 5400 RPM SCSI-2 drives they rate at 28MB/s internal
transfer and 10MB/s external transfer.  Do you think they are saying
the drive has the capability to transfer data+clock bits at 28MB/s
and the SCSI protocol is holding it back to 10?  (I ask Seagate and
their sales people won't speculate.)

I know that current disks (40-100 MByte quantums for example) are the
bottle neck in data transfer with the Amiga line of machines.  I am
curious if disks are starting to come out that can transfer data
faster than the SCSI interface.  I tried to calculate disk rotation
speed versus bits per track but that information isn't included for
SCSI disks.  If sustained transfer rates are increasing from 500KB/s
to 2MB/s then there must be more bits per track since the fastest
spinning drives are increasing RPM by only 50%.  

What's the real story in sustained transfer rates?

Dana Bourgeois @ cup.portal.com