Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 8 Aug 2000 10:20:20 -0500 (CDT)
From:      Steven Timm <timm@fnal.gov>
To:        aic7xxx@freebsd.org
Subject:   Write speeds with AIC-7899 SCSI driver
Message-ID:  <Pine.LNX.4.21.0008081015140.13354-100000@sapphire.fnal.gov>

next in thread | raw e-mail | index | archive | help
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




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.LNX.4.21.0008081015140.13354-100000>