Date:	Sat, 4 Apr 1992 22:23:53 +0200
From:	Ove Ewerlid <ewerlid AT pinus DOT slu DOT se>
To:	djgpp AT sun DOT soe DOT clarkson DOT edu
Subject:	Re: Disk cache with DJGPP and in general
Mailer:	VM 5.32 (beta) for GNU Emacs 18.57.6
Status:	O

I just picked up hyperdisk V4.31 (from nic.funet.fi) and it decreased the
compilation time of a file I have from 24 seconds to 12.
That is, the compilation time with smartdrv.sys using 5 Mb is 24 seconds
and ditto with hyperdisk using 5 Mb is 12 seconds.
(In the case of smartdrive I used ramdisk for GCCTMP
 Hyperdisk don't need that if staged write is used.
 Admittedly this is risky but having a cache flush every 2 seconds of idle time 
 seems to make it acceptable. (for me ...))

I'm amazed!  (That I haven't tested hyperdisk before ...)

The compilation uses large libararies (> 1 Mb) and it was mostly during the link phase
that smartdrv.sys failed to do a proper job.  (Lots of disk accesses ...)
With hyperdisk the harddisk is almost never used after the first build.
(Inspite no ramdrive!)
Since the linking must be done for all changes (in particular "just one file changes")
cutting the linking time by 4 is a great win.


Hyperdisk reports that it uses 32k of memory.

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