Michael,

ASIO is double buffered and there is an additional latency of 60 samples caused by the switchbuffers callback routine. This explains your input latency of 7 ms instead of 5.8ms for a 256 sample buffer at 44.1kHz.

To explain the output latency, PortAudio doesn't tell you how many user buffers are assigned for each device. There may be 4 buffers used for your output channels, I believe the sound card makes such decisions and will need to be configured for lower latency output.

-Michael Casey

On Wed, 20 Mar 2002, Michael Iber wrote:

for all who are interested: PD test 14 runs on win98 and win2000 with Tascam428 very stable for input 1/2 (3/4 doesn't work, although recognized at startup). The only thing I do not understand: startup shows me, that the ASIO- and user-buffersize of 256 is accepted. Nevertheless the input latency is 7 ms and output 21 ms!!!!! Why????