To enlighten further, most people's complaints are about not being able to play many clips and/or effects concurrently.stew wrote:Just to enlighten a bit -
Altivec is not the ultimate happy pill for everything. It can accelerate certain operations a lot, others are not affected at all. Optimization would therefore not speed up everything in Live but just some operations. From the outside, without seeing any of Live's DSP source code, we can only guess how much or few Live would gain from Altivec optimization.
So there may be a combination of two problems:
-- inefficient sound engine
-- inefficient effects processing
The sound engine may benefit from use of CoreAudio libraries as opposed to Sound Manager Carbon libraries. This would mean leaving OS 9 users behind. All other audio developers have, so why not Ableton? This will have to be done at some point, anyway.
Effects processing would probably gain immediate benefit from use of Apple's optimized DSP libraries and from some judicious coding. Again this would probably mean dropping custom code and going with the vendor's optimized code, dropping OS 9 support in the process.
Either way, there's plenty of room for improvement -- however marginal it seems to Windows users. While not a magic bullet, it does more or less level the playing field between the fastest G4 and the fastest P4.
And Altivec isn't going anywhere, certainly not with Apple's investment in optimized MPEG2 (DVD), MPEG1 (MP3) and AAC encoders for its software suite.
While targeted to video processing, here is a non-Apple comparison of Altivec with SSE, with hard numbers:
-- http://klicman.org/altivec/
Quoting his conclusions:
"The AltiVec instruction set architecture (ISA) is very well designed and a pleasure to program for. The ability to write AltiVec optimized software in C saves time and avoids the tedium associated with assembly language programming. AltiVec enables G4 processors to compare favorably with x86 processors having significantly higher clock rates."
The following link may be of interest to audio developers:
-- http://developer.apple.com/audio/xaudiooverview.html
-Alex