[PlanetCCRMA] ardour crackle on writes to firewire drive

[Mark Knecht]

John Yates wrote:
> Hi all,
> 
> Trying to get a stable Ardour setup on an HP ZD7001US notebook. All
> is well when recording to the internal drive, however when recording
> to an external firewire drive I'm getting a crackle in the audio
> when the drive performs the writes. It looks like a short burst of
> moderately low level single sample 'ticks' when zooming in on the
> recorded track. Anyone have any suggestions?
> 
> I'm using a Planet install on FC1.
> 2.4.26-1.ll.rhfc1.ccrma kernel.
> ardour-0.9beta11.2-1.rhfc1.ccrma
> jack-audio-connection-kit-0.98.0-2.rhfc1.ccrma
> RME Digiface/Cardbus
> Maxtor OneTouch firewire drive
> 
> Hoping to get more performance from the firewire drive than the
> internal drive.
> 
> John
> 

John,
    You might consider running Benno's latency test program on the drive 
and look at where you need to set Jack latency with this drive.

    Linux1394 has notoriously low performance compared to other OS's. 
Some drives work pretty well, others not so well. Best to test your 
system for what it can really do.

    Also, I use Firewire drives exclusivey under windows for audio 
recording. Look at setting the block (cluster? I'm sleepy) sizes at 
maybe 32K/block instead the more standard 4K/block. this result in lower 
CPU overhead to read or record a track and less fragmentation over time.

Good luck,
Mark