Re: poor sata performance on 2.6

[Ryan Geoffrey Bourgeois <rgb005@latech.edu>]

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

-------------------------------------------------
This mail sent through IMP: http://horde.org/imp/