Charles Baker wrote:
Finally got pd-0.21 to compile on my linux platform. Mea culpa.... I had installed 'egcs' , an experimental gcc 'improvement' (even higher degrees of optimization than standard gcc available ...someone on the csound list reported a major increase in speed in csound compiled with this compiler)...
How much an increase, percentage-wise?
As an aside, I notice an almost 100 % increase on Pentium-100 Linux when I use a 128-sample DAC Block size instead of 64 samples! THis is based on what "top" reports for CPU%, which is also consistent with what the "profile" object reports. However, I don't yet know whether this is perhaps due to the complex timeing interactions between the DAC size and the OSS fragment size and the scheduler advance.
It think it would be usefull if someone else on similar hardware would verify this. IIRC, it's the DACBLKSIZE parameter that I'm speaking of.
That much difference does seem a bit suspicious, but maybe it makes sense due to the tiny first-level cache (each dsp performance loop easily fits in to the cache and runs at breakneck speed). Or could there be some inefficiency in what happens between DSP runs? I looked and didn't immediately see any glaring errors, but ...
But regardless, 128 samples represents just under 3ms at 44100Hz, which isn't too bad compared to MIDI latency. So it's not a bad deal :-)
Larry
-- Larry Troxler -- lt@westnet.com -- Patterson, NY USA --