[PlanetCCRMA] Sine waves in real time

joey.a joey.a" <joey.a at accelerators.co.uk
Sun Oct 21 02:30:03 2007

Message: 1
> From: "Bill Schottstaedt" <bil@ccrma.Stanford.EDU>
> Sent: Saturday, October 20, 2007 8:00 PM
> Subject: [PlanetCCRMA] sine waves in real time
> > "Which processor and clock speed are you using?"
> 3.8 GHz Pentium 4.
(Context: >> In the Scheme version of Snd, I get about 180 such sines)

Thanks. That is a fast clock. From this I get that your Scheme algorithm has
~ 12% the efficiency of the SuperCollider algorithm, if you are running the
CPU flat out, or ~ 23% if you are referring to 50% CPU loading.
Understandable, really, because a look up table should always be faster than
computing a sin (or even a log) function.

> > Although I don't yet understand the syntax you are all using, I don't
think the
> > 44100 KHz referred to below, has anything to do with the above, which
> > will largely dictate how well any given software is going to perform.
> oops - 44.1 KHz -- a typo.

That sounds more like it! Standard audio sampling rate ;-)

Message: 2
From: "Kjetil S. Matheussen" <kjetil.matheussen@notam02.no>
Cc: <joey.a@accelerators.co.uk>
Sent: Saturday, October 20, 2007 12:28 PM
> Its a 4 year old amd xp2800. I could run about 140 voices in realtime at
> 80% cpu usage,

Interesting. Your clock is ~ half the speed of Bill's, yet you appear get ~
the same performance, from the same software.

Does this mean that AMD is ~twice as efficient as Intel, in music
applications, or that Bill has specified for only 50% CPU loading?


> and about 60 voices in non-realtime 100% cpu usage.

Sorry, this does not compute. Which is the typo?