Path: utzoo!attcan!uunet!husc6!cmcl2!rocky8!cucard!ccnysci!alexis
From: alexis@ccnysci.UUCP (Alexis Rosen)
Newsgroups: comp.sys.mac
Subject: Re: Reeks on Disktimer (LONG)
Message-ID: <989@ccnysci.UUCP>
Date: 15 Nov 88 06:59:44 GMT
References: <698@mouse.UUCP> <30643@think.UUCP>
Reply-To: alexis@ccnysci.UUCP (Alexis Rosen)
Lines: 29

In article <30643@think.UUCP> ephraim@vidar.think.com.UUCP (Ephraim Vishniac)
writes (in an article about J. Reeks vs. DiskTimer II):
>                        ... As I mentioned in an earlier posting, data
>transfer rate is highly overrated as a performance measure.  When
>running most applications, seek time is much more important.  Data
>transfer rate becomes most visible in activities such as copying
>files.

This is what I used to think. I always looked for drives with low seek times.
So I bought a Maxtor 140 MB drive in early '87. This drive performed as I
expected and I was very happy with it. Later I bought a Quantum 80 MB unit with
a seek time 50% slower than the Maxtor (28 ms as opposed to 18 ms) which
nevertheless performed much faster in many operations. The speed came from use
of the then-new "fake DMA" mode which used hardware-assisted "blind" reads and
writes on the Mac II. So transfer speed had a major impact on perceived speed.

I still buy drives with the lowest seek times, though (currently CDC/Imprimis
Wrens). This is because I tend to use them for Multi-user file service and
database accesss. Typically, that kind of application is more likely to cause
lots of slow disk seeks.

To summarize, what Ephraim says is true for me. I don't think it's true for
the majority of single-user systems (with the exception of some database jobs).

----
Alexis Rosen                       alexis@dasys1.UUCP  or  alexis@ccnysci.UUCP
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