Path: utzoo!attcan!uunet!husc6!uwvax!oddjob!ncar!ico!scottw
From: scottw@ico.ISC.COM (Scott Wiesner)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Intel 386SX chip & its applications
Message-ID: <6451@ico.ISC.COM>
Date: 24 Jun 88 14:10:29 GMT
References: <234@belltec.UUCP>
Organization: Interactive Systems Corp, Boulder, CO
Lines: 38

in article <234@belltec.UUCP>, jim@belltec.UUCP (Mr. Jim's Own Logon) says:
> 
> 386SX is slightly faster than a 386 with the BS16 line tied low because of
> some changes to the pipelining, but not much faster. For comperable speeds,
> the 386SX will be 55% to 70% as fast as a real 386.
 
My experience with the Compaq 386SX machine is that for normal unix use, 
it feels about the same as a 16 Mhz 386 based machine.  Here are some 
dhrystone2 numbers:

		     compile time	  execute
		real	user	sys	noreg	reg
		----	----	---	-----	---
Compaq 386SX:	43.0	21.6	7.9	2378	2601
Zenith 386:	49.5	15.9	7.2 	3159	3425
Compaq 25 Mhz:	32.3	7.8	4.2	6747	7107  

With -O:

Compaq 386SX:	52.8	31.2	8.7	2825	3105
Zenith 386:	49.7	23.0	7.0	3671	3952
Compaq 25 Mhz:	39.5	11.5	4.3	7716	8130

In fairness to Compaq and Zenith, I should mention that the above machines
are all pre-production boxes.  Things may have changed slightly.  The Zenith
we have seems to have a pretty slow disk.

The little Compaq is a very nice machine.  It's in a smaller than normal (for
and AT) chassis, and is very very quiet.  For pure cpu stuff (based on the
above dhrystones), it looks like it's about 75% of a standard 386 box.  For
what I was doing with it, (software development) it was fine.  The 25 Mhz
Compaq is a real screamer, but has a real bottleneck at the disk.

All the above machines are running Interactive's 386/ix Unix V.3 system.

Scott Wiesner
Interactive Systems
scottw@ico.isc.com