11 Jul
2010
11 Jul
'10
5:21 p.m.
On Sun, Jul 11, 2010 at 04:53:14PM +0200, Ralf Mardorf wrote:
today I compared a default Ubuntu Studio with and
without the
proprietary NVIDIA driver.
OK, so the proprietary driver seems to yield better 'worst latency' values
compared to nouveau. That's kind of odd, anything X-related would have a much
lower priority than the MIDI threads.
Note that for Ubuntu Studio 2 tests failed because of
time out errors
What exactly timed out?
even the tests that were passed with success are
significantly less good,
than the tests with openSUSE, were I set up audio myself.
What might be the difference between Ubuntu and Suse?
------------------------------------------------------------------------
Ubuntu Studio 10.04 amd64
2 x Terratec EWX 24/96 (2 single cards, but 1 virtual card)
Frequency scaling ?
------------------------------------------------------------------------
spinymouse@ubuntu:~$ uname -a
Linux ubuntu 2.6.32-23-preempt #37-Ubuntu SMP PREEMPT Fri Jun 11
10:19:07 UTC 2010 x86_64 GNU/Linux
spinymouse@ubuntu:~$ envy24control
0xcf00, irq 20, Master Clock int 44100
------------------------------------------------------------------------
openSUSE 11.2 amd64
2 x Terratec EWX 24/96 (2 single cards, but 1 virtual card)
Frequency scaling performance
------------------------------------------------------------------------
spinymouse11.2@suse11-2:~> uname -a
Linux suse11-2 2.6.31.6-rt19 #1 SMP PREEMPT RT Wed Nov 18 16:59:26 CET
2009 x86_64 x86_64 x86_64 GNU/Linux
2 differences jump out:
- the frequency scaling is set to 'performance' on your suse install and to
'?' on your ubuntu install.
- The kernel options for your suse install has the options 'SMP PREEMPT RT',
while your ubuntu install has the options 'SMP PREEMPT'. In other words, it
looks like your ubuntu kernel has 'normal' preemption, but not the -rt
patch.
The latter looks like a good candidate for explaining the difference. Could
you test with the kernel from the linux-image-2.6.31-10-rt package instead of
the kernel from the linux-image-2.6.32-21-preempt package which you seem to be
using now?
Kind regards,
Arnout