Re: poor sata performance on 2.6

Ryan Geoffrey Bourgeois
2004-04-15T03:54:56Z

Quoting Konstantin Sobolev <kos@supportwizard.com>:

> /dev/hde:
> Timing buffer-cache reads: 1436 MB in 2.00 seconds = 717.03 MB/sec
> Timing buffered disk reads: 100 MB in 3.03 seconds = 32.95 MB/sec
>
> for sata_sil:
>
> /dev/sda:
> Timing buffer-cache reads: 1412 MB in 2.00 seconds = 705.05 MB/sec
> Timing buffered disk reads: 84 MB in 3.06 seconds = 27.43 MB/sec
>
> So my old IDE HDD appears to be considerably faster. Expected results were
> 55-70MB/s.

Which kernel version did you get these results using? Have you speed-tested the
drive(s) on a different SATA controller? I don't mean to imply that you should
buy another one - that would be rediculuous since your motherboard should
laready has it - but it would help to eliminate possible causes of error. I
took the same readings on my machine. I'm using an ASUS SK8N motherboard -
that's the Promise TX2 SATA controller - with Western Digital's 36gb 10K RPM
Raptor:

/dev/sda:
Timing buffer-cache reads: 128 MB in 0.12 seconds =1075.79 MB/sec
Timing buffered disk reads: 64 MB in 1.20 seconds = 53.43 MB/sec

I'm using the latest stable vanilla kernel (2.6.5), compiled today. It would
also help to have your kernel config, if at all possible.

-Ryan

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