Article View: comp.sys.mac
Article #34442Re: Reeks on Disktimer (LONG)
From: Ephraim Vishniac
Date: Tue, 15 Nov 1988 22:02
Date: Tue, 15 Nov 1988 22:02
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1848 bytes
In article <989@ccnysci.UUCP> alexis@ccnysci.UUCP (Alexis Rosen) writes:
+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.
+This is what I used to think. ... 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.
But the Q280 also has a large (60KB? I don't remember exactly.)
on-board cache. So the seeks may be slower, but they are also
somewhat less frequent. This is a prime example of why benchmarking
or buying disks is so damned complicated. We need an actual usage
test, but I doubt we'll ever agree on one.
Ephraim Vishniac ephraim@think.com
Thinking Machines Corporation / 245 First Street / Cambridge, MA 02142-1214
On two occasions I have been asked, "Pray, Mr. Babbage, if you put
into the machine wrong figures, will the right answers come out?"
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!think!ephraim From: ephraim@think.COM (Ephraim Vishniac) Newsgroups: comp.sys.mac Subject: Re: Reeks on Disktimer (LONG) Message-ID: <31573@think.UUCP> Date: 15 Nov 88 22:02:02 GMT References: <698@mouse.UUCP> <30643@think.UUCP> <989@ccnysci.UUCP> Sender: news@think.UUCP Reply-To: ephraim@vidar.think.com.UUCP (Ephraim Vishniac) Organization: Thinking Machines Corporation, Cambridge MA, USA Lines: 25