Following Lokasennas great thread on measuring and compensating for interface latency (
http://forum.cockos.com/showthread.php?t=48884) I decided to measure my own interface. I have a Lexicon Lambda interface that I usually drive with ASIO4ALL, but there is also a native Lambda ASIO driver. When comparing these two drivers I stumbled on something that I cannot get my mind around. Hopefully someone here can help out...
Reaper reports in the top right corner, asio buffer and approximate latency times. I cannot get to really understand those numbers. Here is what it shows me for different buffer settings:
44.1 kHz, 24 bit wav
ASIO4ALL
128 samples buffer, ~8.6/8.6 ms
256 samples buffer, ~11/11 ms
512 samples buffer, ~17/17 ms
Lambda ASIO
128 samples buffer, ~9.9/9.9 ms
256 samples buffer, ~18/18 ms
512 samples buffer, ~36/36 ms
So, 512 samples buffer is either 17 ms latency or 36 ms... which is it?
Even more... if I do the calculations... for 44.1kHz sampling, there are 44.1 samples/ms, so 512 samples would correspond to (512/44.1 = ) 11.6 ms! Now I'm even more confused...
Furthermore, that double buffer would give double latency time, as in the Lambda ASIO case, seems reasonable. But why would this not be the case with ASIO4ALL?