Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!ulysses!eric From: eric@ulysses.homer.nj.att.com (Eric Lavitsky) Newsgroups: comp.sys.amiga Subject: Re: Hard disk through parallel port Message-ID: <1527@ulysses.homer.nj.att.com> Date: Wed, 17-Dec-86 10:59:47 EST Article-I.D.: ulysses.1527 Posted: Wed Dec 17 10:59:47 1986 Date-Received: Thu, 18-Dec-86 02:50:24 EST References: <634@hp-sdd.HP.COM> <1121@cbmvax.cbmvax.cbm.UUCP> Reply-To: eric@ulysses.UUCP (Eric Lavitsky) Organization: AT&T Bell Laboratories, Murray Hill Lines: 18 Keywords: hard disks, DMA, AmigaDOS >George Robbins (cbmvax!grr) Writes: >Well, since there is no DMA support available for the Parallel Port, the >actual data transfer part of the disk activity will be slower than a DMA >type disk controller attached to the Expansion Bus. A bit of clarification here: George is correct, but: The only thing DMA really buys you on the Amiga currently, is the fact that data trasnfers don't interrupt the CPU. The maximum *actual* throughput for current DMA vs. non DMA disks is currently limited by AmigaDOS, which can only chug through about 35K/Sec. So, a disk on the parallel port, if designed correctly, will get you at least close to that limit and a DMA disk cannot surpass that limit (at least not the ones that currently exist). Of course, if you're not using AmigaDOS, that's another story... Has anyone used the disk benchmark recently posted by Rick Spanbauer on some of the popular Amiga hard disks? Eric