[linux-audio-dev] korg oasys

[David Olofson]

On Friday 21 January 2005 19.37, Paul Davis wrote:
> >There is RTAI/LXRT and RTL, both of which provide various forms of
> >kernel and user space hard real time scheduling. Provided you have
> >compatible drivers (which is no issue when dealing with turn-key
> >systems), you can basically just use one of those instead of
> >Linux/lowlatency to cut worst case latency down to the µs range.
> > The only practical limits are RAM access times (cache misses add
> > to the scheduling latency) and raw processing power.
>
> i don't think you meet the synthesis capabilities they described
> even on a bleeding edge athlon. the voice counts for just the
> wavetable synthesis along are amazing, and you can run KARMA,
> wavetable, subtractive, organ and one other synthesis method all at
> the same time.

That might be a problem, even with heavily optimized SIMD code. :-) 
After all, general purpose CPUs are optimized for dealing with the 
"unpredictable" control flow of normal applications rather than the 
kind of calculation/bandwidth ratios high end DSPs are designed for.

Not much to do with operating systems either way, although the only 
potential solution - massive SMP - depends very much on IPC latency. 
That said, I think you could get away with some CPUs in parallel for 
the synthesis and some more CPUs in parallel for master effects and 
mixdown. Shouldn't be much of a problem, since you can actually 
process one sample at a time reliably (at least at 48 kHz and lower) 
with RTAI or RTL on reasonably good hardware.


//David Olofson - Programmer, Composer, Open Source Advocate

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