Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site ccvaxa
Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcs!ccvaxa!aglew
From: aglew@ccvaxa.UUCP
Newsgroups: net.arch
Subject: Re: RISC vs INTEL
Message-ID: <5100029@ccvaxa>
Date: Thu, 13-Mar-86 21:18:00 EST
Article-I.D.: ccvaxa.5100029
Posted: Thu Mar 13 21:18:00 1986
Date-Received: Sat, 15-Mar-86 19:40:59 EST
References: <117@pyramid>
Lines: 35
Nf-ID: #R:pyramid:-11700:ccvaxa:5100029:000:1613
Nf-From: ccvaxa.UUCP!aglew    Mar 13 20:18:00 1986


>/* Written  6:40 am  Mar 10, 1986 by hammond@petrus in ccvaxa:net.arch */
>I pointed out that a 68000 could do block moves of 32 bit words FASTER
>than the UCB RISC I or II for equivalent memory access times.
>> David Smyth responded:
>> ...
>> So here, RISC at its worst, the same as CISC at its best?
>
>NO WAY, as I pointed out, the 68000 has 16 bit data bus (i.e. 2 memory
>cycles for each read and write of 32 bit words) while the RISC I & II
>have a 32 bit data bus.  IF the CISC 68000 had the same size data bus
>it would save 2 memory cycles, out of a total of 7 or be about 30%
>faster than the RISC.  Of course this benchmark is never included for
>RISC vs CISC comparisons.  However, copy loops occur much more frequently
>in real code than benchmarks such as Ackermann's function.
>
>Rich Hammond

Well, let's be fair. How about looking at the benchmarks RISC did include?
Not just Ackerman's function.

In `A VLSI RISC', Computer 1982, Patterson and Sequin present SIMULATED
results. Among them:
	SED	- the UNIX stream oriented editor
	Speed   RISC I (sim) / VAX-11/780   1.1
		ie. the VAX is 10% slower on this text processing program
		than RISC

OK, those are simulations. How about some actual results?: `Running RISCs',
Foderaro, Van Dyke, and Patterson, VLSI Design, Sept/Oct 1982. String search.
	MC68000	8 MHz	wait states 2	4.7 ms
	RISC I	1.5 MHz		    0	2.5 ms
There are a lot more recent benchmarks, but this is the one that impressed me.
The very first RISC I, with bugs, a clock rate about a third what they'd
hoped for, ans still they benchmarked faster than a much more mature machine.