Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!decwrl!sgi!shinobu!odin!anchor!olson
From: olson@anchor.esd.sgi.com (Dave Olson)
Newsgroups: comp.sys.sgi
Subject: Re: very fast /tmp and /usr/tmp partitions.
Message-ID: <11489@odin.corp.sgi.com>
Date: 7 Aug 90 17:01:39 GMT
References: <9008070113.AA18462@mcirps2.med.nyu.edu> <1990Aug7.124134.7563@eagle.lerc.nasa.gov>
Sender: news@odin.corp.sgi.com
Organization: Silicon Graphics, Inc.  Mountain View, CA
Lines: 28

In <1990Aug7.124134.7563@eagle.lerc.nasa.gov> fsfacca@ZoSo.lerc.nasa.gov (Tony Facca) writes:

| >Are there any ram disks available for sgi machines, and does anyone have
| >experience with them ? Are they worth it ?
| 
| I think you can probably call the same people who sell those third party 
| inodes. :-)

Actually, there ARE companies that make SCSI based RAM disks.  We measured
sustained throughput of about 4Mb a second on one of them (provided you have a
machine with the IO3 board, or a 4D25).  That isn't blindingly fast, but
it is about twice as fast as the fastest available SCSI disk drives, and
only slightly slower than IPI.

One of the companies making such drives is Ramstor, someplace in Colorado.
They aren't cheap, and of course we are not endorsing them, saying they will
work for you, etc., etc.

CPU memory based RAM disks really aren't all that great, since unless you
have a Power series with 128 Mb of RAM, you probably won't have enough
RAM to help a whole lot.  Irix 3.3 does allow you to use 'all' of 'unused'
memory as part of the buffer/page cache automatically, which can speed
some file accesses quite a bit.
--

	Dave Olson

Life would be so much easier if we could just look at the source code.