From owner-freebsd-hackers Wed Mar 22 00:58:50 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id AAA27283 for hackers-outgoing; Wed, 22 Mar 1995 00:58:50 -0800 Received: from ref.tfs.com (ref.tfs.com [140.145.254.251]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id AAA27276; Wed, 22 Mar 1995 00:58:48 -0800 Received: (from phk@localhost) by ref.tfs.com (8.6.8/8.6.6) id AAA04645; Wed, 22 Mar 1995 00:58:40 -0800 From: Poul-Henning Kamp Message-Id: <199503220858.AAA04645@ref.tfs.com> Subject: Re: Why IDE is bad To: hasty@star-gate.com (Amancio Hasty) Date: Wed, 22 Mar 1995 00:58:39 -0800 (PST) Cc: hackers@FreeBSD.org, faq@FreeBSD.org In-Reply-To: <199503220045.AAA09701@star-gate.com> from "Amancio Hasty" at Mar 22, 95 00:45:54 am Content-Type: text Content-Length: 822 Sender: hackers-owner@FreeBSD.org Precedence: bulk > > I just made a simple test, this shows why IDE is inferior to SCSI for > > FreeBSD: > > > > Western Digital 540 Caviar EIDE disk on IDE controller: > > ------------------------------------------------------- > > Quantum Empire 2100 SCSI-II disk on VL-buslogic controller > > Do the above drives have similar performance characteristics? That is entirely insignificant. The interesting thing is that while your IDE drive transfers data, your CPU is busy. When your SCSI ctrl (for decent controllers at least) transfers data, your CPU can do other things. And we're talking a factor 8 here (twice as much data * one fourth the load). -- Poul-Henning Kamp -- TRW Financial Systems, Inc. 'All relevant people are pertinent' && 'All rude people are impertinent' => 'no rude people are relevant'