Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!husc6!bbn!rochester!cornell!batcomputer!sun.soe.clarkson.edu!nelson
From: nelson@sun.soe.clarkson.edu (Russ Nelson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: PC Cache programs
Message-ID: <1068@sun.soe.clarkson.edu>
Date: 15 Jun 88 15:31:58 GMT
References: <1304@spdcc.COM>
Reply-To: nelson@sun.soe.clarkson.edu (Russ Nelson)
Distribution: na
Organization: Clarkson University, Potsdam, NY
Lines: 65

In article <1304@spdcc.COM> eli@spdcc.UUCP (Steve Elias) writes:
>i've benchmarked the Compaq disk cache on my 10 MHz ALR at and
>the results seem to stink...  i'm using 384k of extended memory 
>as cache...  the result is that using the cache actually slows the
>machine down.  the disk drive is not fast, either:  40 ms st251...
>
>i believe that this can be accounted for by the bios calls necessary
>to switch into and out of protected mode.  the overhead must be slowing
>the cache access down...  any comments ??

Maybe not.  It might depend on your BUFFERS= settings:

					Clarkson University
					Potsdam, NY 13676

John Dvorak
PC Magazine
One Park Ave.
New York, NY 10016

Dear John:

	In the April 12, 1988 PC Magazine (V7N7) Inside Track column, you
mention that your disk cache works better without any BUFFERS statement in
your config.sys.  You piqued my curiosity, so I wrote an autoexec.bat file
that would run chkdsk three times and take the average.  Here are the details:

	Zenith Z-386 (16 Mhz, no memory cache)
	Zenith's MS-DOS 3.21
	Zcache using 1 Meg of extended ram
	32 Meg Hard Disk w/ 28 ms average seek time.


The numbers:

Buffers	Time in hundreths
1	728
2	423
3	316
4	247
5	236
6	238
7	239
8	240
9	252
10	247
11	261
12	258
13	267
14	265
15	274
16	278
17	280
18	289
19	289
20	300
21	297
22	308
23	308
24	311
25	322

-- 
signed char *reply-to-russ(int real_network) {	/* Why can't BITNET use	*/
if (!real_network) return "NELSON@CLUTX";	/* TCP/IP?		*/
else return "nelson@clutx.clarkson.edu"; }