Re: 2.6.0 performance problems

From: Martin Schlemmer
Date: Mon Dec 29 2003 - 20:36:41 EST


On Tue, 2003-12-30 at 03:27, Dave Jones wrote:
> On Mon, Dec 29, 2003 at 07:17:23PM -0500, Thomas Molina wrote:
>
> > > > UDMA modes: udma0 udma1 *udma2 udma3 udma4
> > > > AdvancedPM=yes: mode=0x80 (128) WriteCache=enabled
> > > > Drive conforms to: ATA/ATAPI-5 T13 1321D revision 1:
> > > Any reason it is currently set to udma2 where it support udma4 ?
> >
> > Not really. The question was what mode the disk was running in. This is
> > what it defaults to. This is a laptop drive that only runs at 5400RPM.
> > Would changing the mode to udma4 make a dramatic difference?
>
> It's not uncommon for a laptop to have a hard disk which supports
> higher DMA modes than what the IDE chipset supports.
> My aging Intel 440BX based VAIO has a disk in the same configuration
> as yours, supports udma4, but chipset only goes up to udma2.
>

Right, or as somebody else pointed out, it might not be a 80-pin cable.

Lets rephrase - does it also run in udma2 mode with 2.4 ? And did
you check readahead? In 2.6 it seems that a bigger value is better -
I for instance have to set it to 8192 to have the same performance as
in 2.4 ...


--
Martin Schlemmer

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