Re: 2.4.x vs 2.6.x: denormal handling and audio performance

[Lee Revell <rlrevell@joe-job.com>]

On Mon, 2004-08-09 at 15:19, Fernando Pablo Lopez-Lezcano wrote:
> Hi all, I've been trying to track weird behavior I'm experiencing when
> trying to use 2.6.x for "pro audio" applications and I think I have
> something to report (and some questions). 
> 
> First, the environment. I'm running the Jack low latency server on top
> of two different software installs on the same hardware, one is FC1 +
> 2.4.26 + low latency and preemption patches, the other is FC2 + 2.6.7
> rc2-mm2 + voluntary preemption O3. They are different hard disks swapped
> into the same P4 laptop. Both are running the same source code versions
> of all the audio programs that I use to test (but _not_ the same
> binaries, each one is built in the environment it runs on). 
> 

Have you tried using the exact same binaries under both 2.4 and 2.6? 
This would rule out a compiler issue.

In case anyone thinks this is an application bug, here are some links
pertaining to the P4 denormals-are-zero issue, these were at the bottom
of Fernando's post:

http://gcc.gnu.org/ml/gcc/2001-07/msg02162.html
http://lkml.org/lkml/2003/5/9/144

Lee