[ardour-users] Is 64 bit dual core supported and stable yet?

[Joel White]

Solv (sent by Nabble.com) wrote:

> Hi, I noticed people are using 64 bit with ardour, just wondering 
> about a few things.  I am currently waiting with much excitement on a 
> new system being built for me at this moment in time.  It is a an AMD 
> 64 Dual Core 3800+ with Asus A8N Nforce motherboard. 

I have a A8N-SLI 'board running this processor (these processors?).  So 
far, I am very happy with the results for Linux audio.  Details:

Distro: Gentoo
Kernel: 2.6.14 (Vanilla), SMP PREEMPT
Other: 1GB Ram, SATA harddrive (onboard nVidia controller), nVidia 
GeForce 6600 graphics adaptor (yeah, the tainted driver; I haven't 
worked out how to _not_ use it, yet)
Sound card: MAudio Delta 1010LT

So far, I have run the following audio software pretty much without trouble:

Jack 0.99.0-r1
Ardour (0.99 ~amd64)
Various LADSPA plugins [swh (~amd64), tap, caps]
Audacity (1.2.3-r1 ~amd64)
Muse (0.7.2_pre2 ~amd64)
PD (0.38.4 ~amd64)
jack_convolve 0.0.13
xmms 1.2.10-r15
timidity++ 2.13.2

Everything built fine, and everything runs very nicely.  It is a real 
credit to all the developers who have worked long and hard on this 
software.  It has been a real joy to have things build and run "right 
out of the box" on relatively new hardware like this.

I've pretty much eliminated xruns, running jack at -r44100 -p64 -n2 
(that's as far down as I've pushed it) using realtime-lsm.  In order to 
do this, I found that I had to set the smp_affinity on my 1010LT to only 
one processor. 

Even thought the results are good so far, I still get occasional xruns like:

**** alsa_pcm: xrun of at least 118.867 msecs
(this particular xrun interrupted a recording with my band, which is 
_very_ bad! I was even running capture only and with a longer period, 
just to be sure xruns wouldn't happen!)

and the odd:

delay of 1131462.000 usecs exceeds estimated spare time of 5606.000; 
restart ...
(this type of error comes mostly when audio connections change, but also 
at other times, although the delay isn't usually quite so long)

 From my understanding, both of these time periods indicate something 
very wrong (an xrun of 118+ msecs?? a delay of 1.13+ _sec_?!?!), but I 
haven't been able to track them down, yet.  I've run Ardour recording 8 
tracks for 10+ minutes, stressing the system with X11 tasks, disk 
write/reads/copies, dragging windows around, downloading big files, all 
without a hiccup.  Then, at random times, *blip* - an xrun or the delay 
message. If anyone has any suggestions on debugging this, I'd appreciate 
any advice.

> I have at the moment on my old system being using fedora core 4 and a 
> planetccrma install with ardour without a problem.  I have been told 
> that fedora itself is a pain in the butt for 64 bit at the moment?  Is 
> that true?, and I was wondering if planetccrma had a specific repo for 
> 64 bit support...I couldn't see any specific instructions. 

Don't know about those distros, but gentoo seems to be set up pretty 
well for 64 bit support (or, at least, the support depends directly on 
the 64 bit capability of the underlying apps).  I'm running all 64 bit 
apps (haven't had to run anything 32 bit, yet)

> Also wondering if the '.smp' kernel which supports multiple processors 
> would make use of a dual core processor? 

Yes! (as was indicated in a previous answer to your email)

> Is ardour stable in 64 bit yet? 

Yes, in my experience.  I haven't had ardour crash yet (just "normal" 
usage, though - haven't really banged on it).

> Does ardour benefit from a dual core processor as well? 

I haven't done a SMP/UP comparison, but as Ardour is a threaded app, I 
can't see how it _wouldn't_ benefit.

> I know I should've probably asked these questions before I got the 
> system....but I wasn't thinking!

If your experience is anything like mine, you're in for a lot of fun!

>
> Anyone who has any pointers or links to more information would be much 
> appreciated.
>
> thanks,
> Andy J
> ------------------------------------------------------------------------


Good luck.   And, once again, thanks to everyone who has had a hand in 
developing all this great software!

Joel