Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!munnari.oz.au!uniwa!andreww
From: andreww@uniwa.uwa.oz (Andrew John Williams)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Why buy a DX over an SX?
Message-ID: <1991Apr13.124312.17457@uniwa.uwa.oz>
Date: 13 Apr 91 12:43:12 GMT
Article-I.D.: uniwa.1991Apr13.124312.17457
References: <14534@encore.Encore.COM>
Organization: University of Western Australia
Lines: 35

elliot@xenna.encore.com (Elliot Mednick) writes:

>to cost $200 more (without cache).  What does the 32-bit interface buy you?
>Certainly not CPU performance.  I did some checking and got these SI (5.0)
>numbers:

>CPU      SI (5.0)   Comments
>---      --------   --------
>286-16   12.3       My trusty 286
>386SX-20 12.8       A friend's system; claims that sometimes it is 15
>386DX-20 12.4       C&T, AMI, 2MB 80ns, interleaved, no wait states, no cache
>386DX-25 15.5       Not the same system as above, but same coniguration

>I was under the impression that DX boards (without cache) really scream.
>I have heard claims of up to 24 SI, w/out cache.  What am I missing?
>Either 1) I've tested out cheap DX boards, or 2) I'm comparing SI 5.0
>__
>Elliot Mednick (elliot@encore.com) |  This .signature file is undergoing
>Encore Computer Corp.              |  remodeling for your convenience.
>Marlborough, MA. 01752             |  Please pardon our appearance.

I have a 386DX/25, with an AMI bios and a C&T chipset, 80ns ram, 0WS.
Not sure if its interleaved (dont want to reboot in the middle of
reading news!) and SI gives me a Computing Index of 26.3. This is using
SI version 4.5. I think older versions of SI give very unrealistic
numbers- my system is certainly not 26.3 times as fast as an XT for most
things- more like 12 or so. I would guess the 386 numbers you have are
using the new version of SI, assuming it has been improved (I have never
tried it).
		Andrew Williams
		Physics Department,
		University of Western Australia.

	andrew@earwax.pd.uwa.oz.au  OR
	andreww@uniwa.uwa.oz.au  (note extra w).