Re: SCSI driver speeds
Maybe it's my hardware, but kernel-2.4.0 is faster than 2.4.7 and
2.4.12 on the _same_ box. Which options to set in menuconfig to get at
least the 2.4.0 speed? Also, using the same disk and an AIC-7881U
running RH's 2.4.9-0.18 I get reported 40MB/s and measured 12.5 MB/s.
Lawrence Walton writes:
> Svante Signell [firstname.lastname@example.org] wrote:
> > Hello Debianers,
> > When running kernel-2.4.0 SCSI disk speed is reported at boot time
> > to synchronous at 40MB/s (bios setting), and measured to 19.2 MB/s
> > using hdparm -t /dev/sda. However, when booting kernels 2.4.7 and
> > 2.4.12 speed is going down to reported 11.6 MB/s and measured 9.4
> > MB/s.
> > Tagged Command Queueing is reported enabled on kernels-2.4.7,2.4.12,
> > not on 2.4.0. How to disable at boot and in .config if this is causing
> > the slowdown?
> > I'm running Debian/unstable, kernels are compiled by hand, using make-kpkg.
> > sda is an IBM 8GB DDRS-39130D with a main board controller AIC-7895.
> > Svante
> It might just be your hardware.
> sym53c895-0-<6,*>: FAST-20 WIDE SCSI 40.0 MB/s (50.0 ns, offset 31)
> SCSI device sdd: 35843670 512-byte hdwr sectors (18352 MB)
> Timing buffered disk reads: 64 MB in 2.41 seconds = 26.56 MB/sec
> lawrence@the-penguin:~$ uname -a
> Linux the-penguin 2.4.12-ac3 #2 Tue Oct 16 12:20:46 PDT 2001 i686 unknown
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