Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!daveh From: daveh@cbmvax.commodore.com (Dave Haynie) Newsgroups: comp.arch Subject: Re: why is 33 MHz a popular number? Message-ID: <17213@cbmvax.commodore.com> Date: 8 Jan 91 04:46:50 GMT References: <1990Nov28.021703.28668@weitek.COM> Reply-To: daveh@cbmvax.commodore.com (Dave Haynie) Organization: Commodore, West Chester, PA Lines: 29 In article <1990Nov28.021703.28668@weitek.COM> weaver@weitek.UUCP (Michael Weaver) writes: >In article tom@ssd.csd.harris.com (Tom Horsley) writes: >>I see a lot of the current and near current top of the line RISC chips and >>other microprocessors coming out with a 33MHz clock rate. In a similar way >>the previously most popular number seemed to be 25MHz. >There is no hardware magic about 33 vs 32, and so forth. Well, there is a little hardware magic. If you look at popular clock speeds, and the clock periods that go with them, all is revealed: Popular Speed Actual Speed Clock Cycle 16MHz 16.67MHz 60ns 20MHz 20.00MHz 50ns 25MHz 25.00MHz 40ns 33MHz 33.33MHz 30ns 40MHz 40.00MHz 20ns 50MHz 50.00MHz 15ns Basically, it would seem that chip makers like to give chip testers, designers, etc. (who of course work in ns, not MHz), nice, even numbers to work with, whenever possible. -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "Don't worry, 'bout a thing. 'Cause every little thing, gonna be alright" -Bob Marley