[298] in linux-scsi channel archive
Changing Latency Timer in pci bios for ncr scsi
daemon@ATHENA.MIT.EDU (Andreas Koppenhoefer)
Sat Jun 24 15:22:33 1995
From: Andreas Koppenhoefer <Andreas.Koppenhoefer@studbox.uni-stuttgart.de>
To: linux-scsi@vger.rutgers.edu
Date: Sat, 24 Jun 1995 20:47:46 +0200 (MET DST)
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Hello scsi gurus,
a few months ago someone told me to reduce 'NCR Latency Timer' in my pci
bios (asus sp3g board with ncr scsi chip onboard).
After changing default 80 to 34, scsi access was significatly
faster. hdparm's measurement was 3.5 Mbyte/sec at 80 and 4.4 Mbyte/sec
at 34: 25% speed improvement. Two questions about that...
1. How about reducing 'NCR Latency Timer' more, let me say 10 or (more
dramatically) zero? Should I expect some malfunction, corrupting
filesystem, destroying hardware?
2. If it's safe to use low values on all systems with NCR chipset - I
never had any problems with 34 - then someone (Drew?) probably
should add an optimization entry to drivers/pci/pci.c.
Thanks in advance,
Andreas
- --
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