[Ardour-Users] Denormals

[Carl Hetherington]

On Thu, 29 Dec 2011, Q wrote:

> Why, when every single track and buss in my session has "Protect against 
> denormals" selected and "Use DC bias" is selected under Options > Performance 
>> Denormal handling, is my session still grinding to a halt?
>
> What is the point of selecting "Protect against denormals" on tracks? It 
> doesn't seem to be doing anything as every few minutes the CPU load rises to 
> 100% and then drops back to ~35% a few minutes after the transport is 
> stopped.
>
> Why are the "Flush To Zero" and "Denormals are zero" etc options greyed out 
> when these were available in prior versions of Ardour?

If these are greyed out, it means that Ardour thinks your processor 
doesn't support those options.  Has your system changed since you were 
using a version which didn't grey these out?

> Going through and deactivating plugins hasn't shown any obvious culprits.

Do you see the problems with no plugins at all?

> I'm using 2.8.12, built from source.
>
> In the time it's taken to write this things have got worse -- with the 
> transport not running the CPU load is 100% all the time and racking up 
> thousands of xruns (does "Stop plugins with transport" have no effect?).

I believe this option is broken in 2.0 and doesn't do anything.

Carl