FreeBSD IO Performance (was Re: Quality of FreeBSD)

[Bohdan Horst]

On Mon, Jul 25, 2005 at 06:00:21PM +0200, Bohdan Horst wrote:
> On Mon, Jul 25, 2005 at 10:15:41PM +1200, Mark Kirkwood wrote:
> > Hmm - looks like I missed that thread, never mind - repeatability of 
> > findings is sound scientific principle :-)
> > 
> > With respect to changing the default for vfs.read_max - makes sense to 
> > me, but it would be interesting to know if anyone has a system that 
> > performs *worse* with it set to 16.
> > 
> > regards
> > 
> > Mark
> > 
> > Chris wrote:
> > >Its been mentioned before and most experience the same as you by
> > >setting it to 16 a dramatic improvement in the sequential read, I
> > >currently run all my 5.x servers like this with no issues as a result.
> > > I am curious if the default will ever be changed.
> 
> on my notebook:
> IBM TP 600x
> 5.4-RELEASE-p4
> ad0: 38154MB <IC25N040ATCS04-0/CA4OA71A> [77520/16/63] at ata0-master UDMA33
> APM enable (but same effect with disable APM)
> AAC unfortunatelly not supported :(
> 
> 
> anything above vfs.read_max=1 produce very annoying little sound (i can
> hear disk heads) when playing movies..

new notebook, new results:

Toshiba 1410-614
5.4-RELEASE-p7
atapci0: <Intel ICH3 UDMA100 controller>
ad0: 38154MB <WDC WD400VE-75HDT0/09.07D09> [77520/16/63] at ata0-master UDMA100

anything above vfs.read_max=1 produce sometimes very annoying little
image glitch/freeze (synchronized with hdd led) when playing movies...
(with AAC disk is now silent:)

regards

-- 
Bohdan 'Nexus' Horst