Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!xrtll!silver
From: silver@xrtll.uucp (Hi Ho Silver)
Newsgroups: comp.sys.ibm.pc
Subject: Re: More disk cache tests
Message-ID: <1990Jul1.003125.18399@xrtll.uucp>
Date: 1 Jul 90 00:31:25 GMT
References: <12988@shlump.nac.dec.com>
Reply-To: silver@xrtll.UUCP (Hi Ho Silver)
Organization: Not around here, pal!
Lines: 69

In <12988@shlump.nac.dec.com> reisert@ricks.enet.dec.com (Jim Reisert) writes:
[...]
$These tests were made using a 384K cache in EXPAnded memory:
$SMARTDRV	35.06	7.26	4.00	3.33	 "
$PC-CACHE 6.03	13.13	8.53	3.14	2.75	 "
$SuperPCK 3.56	 8.52	4.94	1.83	2.45	 "
[...]
$These tests were made using a 384K cache in EXTEnded memory:
$SMARTDRV	34.85	7.25	4.01	3.37
$PC-CACHE 5.5	29.56	6.51	3.61	3.01
$PC-CACHE 6.03	12.50	8.64	4.88	3.87
$SuperPCK 3.56	11.07	5.21	3.56	2.36
$SuperPCK 3.19	 6.00	5.79	1.60	2.54

[CORETEST results deleted]

$I don't know what to make of these measurements.  These say that if you're
$using EXTEnded memory, SMARTDRV is the way to go, but if you're using
$EXPAnded, then use PC-CACHE 6.03.  The PC-Labs Benchmark Tests clearly show

   It's apparent that you don't know what to make of these measurements.
In extended memory, SuperPCK (both versions) beat SMARTDRV in all cases,
so why do you say SMARTDRV is better?  And in expanded memory, SuperPCK
beat PC-Cache in all cases, so why do you say PC-Cache is better?

$Super PC-Kwik to be superior in all categories.  Furthermore, for the

   Your tests also show this.

$I merely offer this up for discussion, since I'm not sure what to make of it
$all.  I'm going to stick with Super PC-Kwik, though.  Anyone care to comment
$on any of this?

   Sure.  Here are a few more things to consider:

- Using a utility such as CORETEST to measure the performance of a disk
  cache is futile, since the activity it performs (repeatedly reading the
  same information) is not a typical task in the real world and, furthermore,
  is the situation in which disk caches excel the most.

- The relative performance of various caches will depend on your hardware.
  For example, of the caches mentioned above, some may be aware when they
  are running on a 386 while others may not.  If using extended memory,
  this will make a huge performance difference since the 386-aware caches
  will realize they don't have to reset the processor to return to real
  mode like they do on a 286.  Other factors which vary the performance
  in varying degrees include the speed of your memory and the data
  transfer rate and seek time of your hard drive.

- Changing the size of your cache, as well as tweaking some of the
  parameters which better caches allow you to do, will alter the
  relative performance levels of the caches.

- One advantage which SMARTDRV has, if you're running Windows, is that
  it will dynamically alter the amount of memory it's using in response
  to Windows' memory requirements.  This is about the only reason I can
  think of why anyone would want to use SMARTDRV.

- Every user will benefit differently from a cache, since every user
  performs a different mix of activity.  As you can see from the
  tables, some caches perform better on some tests and worse on others.
  The best cache for someone who edits, compiles and tests programs may
  or may not be the same as the best cache for someone who does heavy
  database work, even on the same hardware.
-- 
   /Nikebo \ Nikebo says "Nikebo knows how to post.  Just do it."\silver@xrtll/
  /---------\_____________________________________________________\----------/
 /yunexus!xrtll!silver (L, not 1)\ Hi Ho Silver \   just silver for short   /
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