Path: utzoo!mnetor!uunet!husc6!uwvax!oddjob!sphinx!z7m8
From: z7m8@sphinx.uchicago.edu (ari shlomo zymelman)
Newsgroups: comp.sys.ibm.pc
Subject: Re: index of Model 30
Message-ID: <2935@sphinx.uchicago.edu>
Date: 14 Dec 87 02:24:39 GMT
References: <36300005@iuvax> <2635@watcgl.waterloo.edu>
Reply-To: z7m8@sphinx.uchicago.edu.UUCP (ari shlomo zymelman)
Organization: U Chicago Computation Center
Lines: 26


	 You are observing the uselessness of the SI benchmark.
	 SI does a lot of processor intensive work, such as
	 multiplication.  The V20 is very good at such things,
	 and thus can do the 1.8 times as fast as an 8088.
	 However, for normal processing, which is more bus
	 intensive, the 8 bit bus on the 8088/V20 is the
	 bottleneck.  This is why you will only observe a 5-10%
	 improvement with the V20 for general processing tasks.

	 The Model 30 on the other hand has a 16 bit 8086, which
	 means it can fetch twice as much data in one bus cycle,
	 thus speeding up operations quite a bit for average
	 processing.  The '86 in the Model 30 also runs at 6Mhz
	 instead of 4.77, which also increases the speed.

	 So, the 1.9 reading for your model 30 is probably
	 pretty close to a useful result, indicating that the 30
	 is about 1.9 times as fast.  However, SI is useless at
	 comparing V20's with 808x's.

Could someone please comment on the difference between the new PS/2 30
and the AT&T 6300 which also has an 8086.  Is there any speed difference, 
or is IBM finally putting out a comparable machine?

-- Ari Zymelman