Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!cbmvax!daveh From: daveh@cbmvax.UUCP Newsgroups: comp.sys.amiga Subject: Re: MIPS, Turbo Amiga, Mac II Message-ID: <1545@cbmvax.cbmvax.cbm.UUCP> Date: Thu, 12-Mar-87 13:19:42 EST Article-I.D.: cbmvax.1545 Posted: Thu Mar 12 13:19:42 1987 Date-Received: Fri, 13-Mar-87 21:01:48 EST References: <897@crash.CTS.COM> Organization: Commodore Technology, West Chester, PA Lines: 30 in article <897@crash.CTS.COM>, billk@pnet01.CTS.COM (Bill Kelly) says: > > Oh. I thought MIPS was Million Instructions Per Second. You know, 5 MIPS > meant 5 million instructions per second. Is that wrong? > Bill Kelly No that's correct. But its still an arbitrary measurement. We all know what a "second" is, but what's an "instruction". If you were benchmarking the 80386 chip, you might decide to calculate how many NOPs the chip can execute per second. A 68020 benchmarker might choose to do something a little more useful, like benchmark the number of add instructions per second the chip can perform. But do you want 8, 16, or 32 bit adds? Register to register or memory to register? So then we start talking about things like average and peak MIPS. Peak is probably the number of the fastest instruction of any kind (maybe a NOP) that can be executed in a second. Average? Well, it could be a simple average of all possible instructions in all possible addressing modes. But that drags the performance down with all kinds of powerful-yet-esoteric instructions that take a long time to run and are rarely used in real life. So you can see that in practical terms a MIPS figure without lots of further information can be pretty meaningless. By the way, did I mention that the C128 can run at over 1 MIPS? -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dave Haynie Commodore Technology // /| ___ __ __ __ {ihnp4|caip|rutgers}!cbmvax!daveh |\ // /_| | / \ / \ / \ Commodore rarely admits to knowing me, \\// / | +--+ | | | | | | much less sharing my personal opinions. \/ / | |___ \__/ \__/ \__/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~