From owner-freebsd-hackers Mon May 8 14:52:30 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id OAA23655 for hackers-outgoing; Mon, 8 May 1995 14:52:30 -0700 Received: from estienne.cs.berkeley.edu (estienne.CS.Berkeley.EDU [128.32.42.147]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id OAA23649 for ; Mon, 8 May 1995 14:52:29 -0700 Received: from localhost (localhost [127.0.0.1]) by estienne.cs.berkeley.edu (8.6.11/8.6.9) with SMTP id OAA02666; Mon, 8 May 1995 14:51:27 -0700 Message-Id: <199505082151.OAA02666@estienne.cs.berkeley.edu> X-Authentication-Warning: estienne.cs.berkeley.edu: Host localhost didn't use HELO protocol To: Tom Samplonius cc: hackers@FreeBSD.org Subject: Re: Is a 486 fast enough for SCSI? In-reply-to: Your message of "Mon, 08 May 1995 12:26:33 PDT." Date: Mon, 08 May 1995 14:51:27 -0700 From: "Justin T. Gibbs" Sender: hackers-owner@FreeBSD.org Precedence: bulk > > I've got a AMD486DX4100 with an Adaptec 2940 and two SCSI drives. When >I run iozone on one drive I get about 1.9MB/s, but when I run a iozone on >each drive I get about .9 MB/s (roughly half). Since the SCSI bus runs >at 10MB/s per second, the limiting factor appears to be the CPU? I >thought PCI devices required very little CPU time? > >Tom Do you have disconnection disabled on your devices? I don't see anywhere neer this kind of performance drop off on my 2742 with two drives (One drive is 5MB/s the other is 2MB/s). -- Justin T. Gibbs ============================================== TCS Instructional Group - Programmer/Analyst 1 Cory | Po | Danube | Volga | Parker | Torus ==============================================