Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!orstcs!ogccse!blake!seymour
From: seymour@blake.acs.washington.edu (Richard Seymour)
Newsgroups: comp.periphs
Subject: Re: Hard drive speeds
Message-ID: <3459@blake.acs.washington.edu>
Date: 1 Sep 89 23:02:51 GMT
References: <17640@ut-emx.UUCP> <3170009@hprnd.HP.COM>
Reply-To: seymour@blake.acs.washington.edu (Richard Seymour)
Organization: University of Washington, Seattle
Lines: 18

In article <3170009@hprnd.HP.COM> kc@hprnd.HP.COM (Kurt Chan) writes:
>> As seek times approach rotational latency the speed
>> with which the data may be accessed will be dominated by rotational
>> latency and controller behavior, not by seek times. 
>
>Disk manufacturers have come up with solutions to this exact problem.  Some HP
>drives now spin at 4000 RPM, while Hitachi and Imprimis have drives which rev
>up to 4800 and 5400 RPM, respectively!
>
And then there was DEC: in 1978 they wanted to put an 80mbyte CDC SMD drive
on Unibus machines, but its data rate was too high for the Unibus.
So they dropped the speed from 3600 rpm to 2400 rpm.
And the RM-02 was born!  (the RM-03 was the quick one...)
There were a (very) few changes in the electronics to support the
lower frequencies coming off the heads, but the disks were directly
swappable with full-speed RM-03s.
We had one... it ran just fine...
-- dick