mkfs gap option

Geoff Steckel - Sun BOS Software gsteckel at diag2.East.Sun.COM
Wed May 2 02:33:36 AEST 1990

In article <PCG.90Apr30221039 at> pcg at (Piercarlo Grandi) writes:
>This value of 3600 RPM has been constant for the past 30 years. from
>mainframes to micros, and for good (e.g. mechanical) cause. There have
>been steady improvements in seek times and bandwidth, and rotational
>latency is thus becoming the bottleneck. Palliatives revolve around the
>multiple arm idea, i.e.  reinventing drums, e.g. disc arrays (introduced
>to the 386 world by compaq or zenith recently).

In general this is true, but:

Some CDC->Imprimis->Seagate drives (including the `Wren Runner', I believe)
have gone as high as 5400 RPM.  This allows the rotational latency to be
reduced to 6 or less milliseconds, at a cost of a 50% higher transfer rate.
There may be other manufacturers playing the same game, since this makes
a very snappy drive.  Also, some of the zone-recording compromises are easier
to make at a high data rate rather than a low one.

In the other direction, some of the (now obsolete) 9" and 14" SMD drives
used 2100 and 2400 RPM to slow down the transfer rate low enough to meet
maximum rate limits on old equipment.  You could change a belt & pulley
arrangement if you wanted faster bits...
	geoff steckel (gwes at wjh12.harvard.EDU)
Disclaimer: I am not affiliated with Sun Microsystems, despite the From: line.
This posting is entirely the author's responsibility.

More information about the Comp.unix.i386 mailing list