From owner-freebsd-current Sat Feb 20 12:59:55 1999 Delivered-To: freebsd-current@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 2011B11851 for ; Sat, 20 Feb 1999 12:59:53 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id MAA11080; Sat, 20 Feb 1999 12:58:32 -0800 (PST) (envelope-from dillon) Date: Sat, 20 Feb 1999 12:58:32 -0800 (PST) From: Matthew Dillon Message-Id: <199902202058.MAA11080@apollo.backplane.com> To: Paul van der Zwan Cc: "Kenneth D. Merry" , freebsd-current@FreeBSD.ORG Subject: Re: Slow seq. write on Seagate ST36530N References: <199902201159.MAA01220@trantor.xs4all.nl> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :This did not improve anything , but I think I have found the couse. :In that modepage there is a DISC value which was 0 on the IBM and 1 on the :Seagate. I remembered a ' Enable disconnect' option in the Adaptec 2940 bios, :setting this to 'off' for both harddisks led to a huge performance increase on :the Seagate. If I also enable Ultra mode iozone write goes from 1.5 MB/s :to 12 MB/s ( a factor of 8 !!!). : : Paul : :-- :Paul van der Zwan paulz @ trantor.xs4all.nl There's something wrong. Disconnection should not cause that sort of performance decrease. Disconnection is necessary if you want to maintain preformance with more then one scsi device on the scsi bus. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message