Re: [PATCH] speed up SATA

From: Jens Axboe
Date: Mon Mar 29 2004 - 03:19:56 EST


On Sun, Mar 28 2004, Wim Coekaerts wrote:
> > In 2.4 reaching 512k DMA units that helped a lot, but going past 512k
> > didn't help in my measurements. 1M maybe these days is needed (as Jens
> > suggested) but >1M still sounds overkill and I completely agree with
> > Jens about that.
>
> at least 1Mb... more than 1mb (I doubt 32mb is really necessarily
> useful) is nice for flushing contiguous journal data to disk. between
> 1-8mb in one io.

'is nice' means what, in real numbers? :)

> at least 1mb is good when you have to process massive amounts of data,
> just read huge chunks of files, we tend to do 1mb. anyway,
> as you said, at some point it's a bit overkill . I thinkg 1-8mb makes
> sense.

Yeah, that _range_ makes sense. 1MB is a lot more supportable than 8MB
though, so the benefit needs to be something more than a feel good
sensation.

--
Jens Axboe

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