Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!watcgl!watmum!smvorkoetter From: smvorkoetter@watmum.UUCP Newsgroups: comp.sys.ibm.pc Subject: Re: index of Model 30 Message-ID: <2635@watcgl.waterloo.edu> Date: Tue, 8-Dec-87 09:17:55 EST Article-I.D.: watcgl.2635 Posted: Tue Dec 8 09:17:55 1987 Date-Received: Sun, 13-Dec-87 02:38:19 EST References: <36300005@iuvax> Sender: daemon@watcgl.waterloo.edu Reply-To: smvorkoetter@watmum.waterloo.edu (Stefan M. Vorkoetter) Organization: U. of Waterloo, Ontario Lines: 26 In article <36300005@iuvax> bose@iuvax.cs.indiana.edu writes: > >The Norton SI index for the PS/2 Model 30 is 1.9. My PC XT has a SI index >of 1.8 with a V20 chip. However the Model 30 seems to run faster. > >Can anyone tell me what it is that I am observing? 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. Stefan Vorkoetter Symbolic Computation Group University of Waterloo