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