hi
the measurements i have done with the HDSP/winXP have not been very satisfying. the main problem used to be, that measurements tended to be not-reproducable under winXP (as they were under linux)
test system was an athlon-XP3200+ machine (winXP-pro).
I seem to be luckier I didn't make any objective measurements, but hearing it I get very good results
My PC is a Shuttle SB51 with P4 2.4GHz, and WinXP pro, and also Linux
as far as i remember i didn't use the "-blocksize" option (don't know why; probably it had no effect)
I think this regards the pd internal vector size ; the smallest it is and the most performant it is (but more CPU too) ; default is 64 samples ... I put it to 128, it's stupid of course I thought it corresponded to the sound card I/0 vector size (I should have used "-audiobuf" of course)
the "-audiobuf" should be at least the corresponding value to the buffer-size you set at the control-panel (for a buffersize of 128, use 3ms of audiobuf)
i didn't get any reasonable results with a buffer-size below 256. the best result i got was about 2179 samples (which is 50ms @ 44.1kHz) but it was not very stable (at least at at CPU-load of 80%) (but it really performed quite erratically: e.g: with an rme-buffer of 2048 samples (which gave me a latency of 6019 samples) i didn't get *any* good signal, even at a virtual load of 0% !!)
that was the main reason, why we chose to use linux even more for latency-critical applications. (at least we could do 835 samples latency with a load of 50% on the same machine with alsa/jack; and without file-access (this does not mean writing to soundfiles, but rather saving big-files at once) during dsp-processing the system gave us a stable latency of 1603 samples at 80% cpu-load)
well, I prefer Linux too, but I have complex ALSA problems because my HDSP was too recent -- it should have been fixed now, and I will try to re-install Linux PlanetCCRMA ... in april (loads of work since september !)
big tip: use your task-manager to prioritize the pd thread to "real-time" and the pdgui-thread (wish83) to "lowest".
will try this
thanks a lot for you advices
j