[linux-audio-dev] Old hat - comparison against windows

[Steve Harris]

On 30 Jan 2007, at 17:03, Michael Ost wrote:

> Can anyone suggest ways to compare audio/midi performance between  
> Linux
> and Windows that (1) are relevant to non-technical musicians and (2)
> make Linux compare favorably?
>
> Not things like "I just don't like Windows" or software feature
> comparisons or the politics of open vs. closed source, but rather  
> things
> like responsiveness to audio interrupts, RAM footprint of the OS  
> and ...?
>
> I work for a company that sells a Linux based piece of hardware that
> plays windows VSTs. We spend alot of time on compatibility,   
> especially
> on getting the plugins to work with Wine. I often get asked about
> switching to Windows and I don't have a good answer.
>
> My sense is that the main benefit of Linux is that audio interrupts  
> are
> serviced faster and more predictably than in Windows because of
> SCHED_FIFO and Linux's low overhead. And clearly musicians could feel
> that, especially at lower buffer size settings so that's the kind of
> thing that could matter.

I would have thought that the best way to measure scheduler  
performance is to write a simple VST plugin that writes the precise  
time at which it was called into a ram buffer, and writes the buffer  
out to disk after a few tens of thousands of calls.

You can the measure the times between adjacent runs and work out if  
there's any significant difference in jitter.

I would think that the RAM footprint is essentially impossible to  
measure, as you can't tell what proportion of the kernel space is  
buffers etc.

 From a commercial point of view, your are at the very least saving  
licence fees for each piece of hardware, that would surely eat into  
your profit margin.

- Steve