Subject: Re: [linux-audio-user] Ardour - xrun in Atlhon 2.8 !?
From: Eric Dantan Rzewnicki (rzewnickie_AT_rfa.org)
Date: Fri Sep 10 2004 - 22:52:36 EEST
On Fri, Sep 10, 2004 at 12:53:30PM -0300, Alexander Franca wrote:
> Recording:
> ---------------------------------------------------------------------
> /dev/hda:
> Timing buffer-cache reads: 820 MB in 2.01 seconds = 408.43 MB/sec
> Timing buffered disk reads: 10 MB in 3.38 seconds = 2.96 MB/sec
>
> Without Record:
> ---------------------------------------------------------------------
> /dev/hda:
> Timing buffer-cache reads: 852 MB in 2.01 seconds = 423.94 MB/sec
> Timing buffered disk reads: 8 MB in 3.00 seconds = 2.66 MB/sec
>
> Recording again:
> ---------------------------------------------------------------------
> /dev/hda:
> Timing buffer-cache reads: 812 MB in 2.00 seconds = 405.25 MB/sec
> Timing buffered disk reads: 10 MB in 3.66 seconds = 2.74 MB/sec
>
> Runing Jack
> ---------------------------------------------------------------------
> /dev/hda:
> Timing buffer-cache reads: 1028 MB in 2.00 seconds = 512.80 MB/sec
> Timing buffered disk reads: 10 MB in 3.26 seconds = 3.07 MB/sec
ooOOoo. those are really low. You should expect to be getting more on
the order of 20-30 MB/sec for buffered disk reads. I've never worried
about buffer-cache reads, doesn't really mean a whole lot for sustained
i/o in my experience.
I get upwards of 40MB/s at home on ATA133 drives. You need to tweak your
kernel config and/or set some dma and other options with hdparm.
-Eric Rz.
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