[LAU] ACPI, HW and Jack issues? "[solved]"

Jostein Chr. Andersen jostein at vait.se
Thu May 14 03:09:43 EDT 2009


On Wednesday 13 May 2009 22.50.08 Brent Busby wrote:
...
> Wow...just for reference, what kind of motherboard/cpu was this?  There
> are probably a lot of people (like me) that would like to know the
> hardware when a success story is achieved.  Also, what audio card and
> distro?
>
> (Less than a millisecond??)  :-O

Yes, less than a millisecond. :-) ..but I still have to send "nosmp" to the 
kernel in Grub's menu.lst-file - or the system freezes; I wasn't aware of that 
when I wrote to this list yesterday - so it's still a lot of potential for 
improvements; just as with the proprietary nvidia driver for  my previos GPU,  
the proprietary ATI driver don't play nice with the rt-kernel, but I have a 
much quicker and stable sustem with the ST GPU. So I guess that it's a problem 
with the Ubuntu RT-kernel (2.6.28-3-rt) and possible in combination with some 
motherboard issues that I haven't figured out yet.

Anyway, the system is quick and stable even with this quirks, here are the 
specs (and some extended info because I'm in the mood for it):

MB:   MSI K9N SLI Platinum
CPU:  Athlon64 X2 6400+, 3.2 GHz
RAM:  8GB: 2 * Kingston ValueR. DDR2 PC6400 4096MB CL5, Kit w/two
      matched ValueRAM 2048MB DDR2 (total of 4 pieces)
GPU:  Asus Radeon HD 3450 256MB DDR2, PCI-Express 2.0, DVI, Passive
      (that means no fan, making the machine more quiet)
SC:   M-Audio DELTA 1010 which is Jack driven and the ALSA driven
      MB's card, an Intel HDA, which serves for light monitoring and
      ordinary usage purposes.     
OS:   Kubuntu 9.04 64 bit with 2.6.28-3-rt running and with almost
      every music related apps and libraries compiled from scratch.
Jack: In normal use, the setting are: Frames: 64, sample rate 44100,
      periods: 2 which gives 2.9 ms of latency. I normally reduce
      the frames down to 16 (0.726 ms) when i do recording and up
      to 512 (23.2 ms) and rarely even up to 1024 (46.4 ms) when
      mixing. I have experienced xruns if the latency is to high,
      perhaps some apps or HW are impatience? :-)

I suspect that the MSI K9N is not an ideal solution for Audio, but that the 
power of CPU and the system at large makes everything good anyway.

The main apps are Ardour, Rosegarden and Linuxsampler (loaded with  4-5 GB of 
sounds, NDK, pianos, brass and bass) and occasionally zynaddsubfx and  
FluidSynth (Qsynth). 

I use to do files in 44100 and 24 bit. I believe that 48000 is not (very) 
audible, in order to be audible it should be 96000 which I'm not ready to use 
as a standard yet. I always record samples and synths and any sequencer 
related stuff into Ardour before mixing, freeing resources to plugins. 
Speaking of plugins: I really love the Calf plugins, especially the compressor 
for drums, awesome! For Guitar work, I use a POD or micing up amplifiers with 
SM 57's. IMO the POD sounds great in the mix, but the compressor really sucks, 
so I have a Marshall ED-1 first in the chain when using guitars with low 
output SC. I use QtPod for controlling the POD from the computer. Keyboard 
controller is an Edirol PCR 800.

The average or sane user will probably use a ready music distro or additions 
like CCRMA with the apps from the repository. I use Kubuntu because I like it 
and mainly use Ubuntu (both desktop and servers) for work. This makes my life 
easier. I also use a similar setup on my Laptop, but with a Edirol UM-2ex 
interface for MIDI and a M-Audio MobilePRE USB audio interface.

I hope that this info can be of some value for someone that wonders where to 
go or just are interested.

Jostein






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