From owner-freebsd-questions Sat Nov 6 5:51:32 1999 Delivered-To: freebsd-questions@freebsd.org Received: from funkthat.com (adsl-63-195-54-213.dsl.snfc21.pacbell.net [63.195.54.213]) by hub.freebsd.org (Postfix) with ESMTP id 2AF9314D6F for ; Sat, 6 Nov 1999 05:51:30 -0800 (PST) (envelope-from gurney_j@efn.org) Received: (from jmg@localhost) by funkthat.com (8.9.1/8.8.7) id FAA10689; Sat, 6 Nov 1999 05:51:08 -0800 (PST) Message-ID: <19991106055108.38507@hydrogen.fircrest.net> Date: Sat, 6 Nov 1999 05:51:08 -0800 From: John-Mark Gurney To: David Miller Cc: Rob Snow , freebsd-questions@freebsd.org Subject: Re: writing much slower than reading... References: <38240CC0.8099D19D@lgc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.69 In-Reply-To: ; from David Miller on Sat, Nov 06, 1999 at 07:45:16AM -0500 Reply-To: John-Mark Gurney Organization: Cu Networking X-Operating-System: FreeBSD 3.0-RELEASE i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG David Miller scribbled this message on Nov 6: > John is commenting on the 1.68 sec cpu time required to write 128 MB. > > Isn't this just a normal result of IDE vs scsi? If IDE is going to be as > fast and cpu un-intensive as scsi I wasted a lot of money on my last bunch > of servers:) IDE has improved a bunch w/ DMA support and other things... sure, it still has limitations, but for a single drive system, IDE is great... you are problably thinking back when IDE didn't support busmastering, and required poll io to get the data across... and actually, IDE has a lower command latency than SCSI (see Bruce Evans's posting about it on -hackers or -current a long time ago)... IDE's Problems: two drives can't talk on the channel at once until the other has completed can't queue up commands like scsi only two drives per channel SCSI's Problems: expensive wiring can be tricky because of supporting 7 or 15 devices -- John-Mark Gurney Voice: +1 408 975 9651 Cu Networking "The soul contains in itself the event that shall presently befall it. The event is only the actualizing of its thought." -- Ralph Waldo Emerson To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message