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
.- Audiality -----------------------------------------------.
| Free/Open Source audio engine for games and multimedia. |
| MIDI, modular synthesis, real time effects, scripting,... |
`----------------------------------->
http://audiality.org -'
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