From owner-aic7xxx Tue Aug 8 8:20:24 2000 Delivered-To: aic7xxx@freebsd.org Received: from sapphire.fnal.gov (sapphire.fnal.gov [131.225.81.94]) by hub.freebsd.org (Postfix) with ESMTP id 1796E37B5AE for ; Tue, 8 Aug 2000 08:20:21 -0700 (PDT) (envelope-from timm@fnal.gov) Received: from localhost (timm@localhost) by sapphire.fnal.gov (8.9.3/8.9.3) with ESMTP id KAA13358 for ; Tue, 8 Aug 2000 10:20:20 -0500 X-Authentication-Warning: sapphire.fnal.gov: timm owned process doing -bs Date: Tue, 8 Aug 2000 10:20:20 -0500 (CDT) From: Steven Timm To: aic7xxx@freebsd.org Subject: Write speeds with AIC-7899 SCSI driver Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-aic7xxx@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org A couple of weeks ago I posted to this list that I had been having problems with a AIC-7899 Ultra-160 SCSI controller under Linux. Symptom of the problem was that write speeds were slow, < 10 Mb/sec, although the bus and drives should have been good for at least 30 MB/sec. Later versions of the driver (5.1.30,5.1.31) and later kernels 2.2.16 and greater were even worse. The problem still persists under Linux but I have now loaded FreeBSD on the machine as well (from which I understand Linux derives this particular driver) and the performance was fine..32 MB/sec write and 33 MB/sec read using bonnie, which is essentially the hardware limit of the Seagate Cheetah drive as I understand it. Does someone know why a driver with similar parentage would behave under FreeBSD but not under Linux? Perhaps this will help someone sort out the problem. The non-performance under Linux cost the vendor a contract. ------------------------------------------------------------------ Steven C. Timm (630) 840-8525 timm@fnal.gov http://home.fnal.gov/~timm/ Fermilab Computing Division/Operating Systems Support Central Systems Support Group--Computing Farms Operations To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message