19 Jul
2002
19 Jul
'02
1:57 a.m.
hi list
did anybody watch this phenomenon:
the CPU is a PII 800 MHz; I tried under w2k and linux; a patch with some sample-loops and LFOs consumes 50% cpu-power. adding some (10 .. 20) filters of iemlib (like hp1~) it eats up to 100 % (after 5 minutes). in my test-patches, one filter takes about 0.1 to 0.2 %. I figured out, if there is no signal in, the IIR-filters produce NaNs. I think, Miller wrote in his sources of "d_filter.c" a NAN-protection. but it did not work very well for me. I added to each filter a white-noise-signal multiplied by "*~ 1e-10" (-200 dB), now the filters are cpu-power-stable. (I generate only once, and then i sended it with s~ and r~)
Thomas Musil