On Fri, Feb 20, 2009 at 10:37 AM, Eric Wachsmann <e...@flex-radio.com> wrote: > The maximum audio buffer size in PowerSDR is 2048, so I wouldn't recommend > going higher than that in the driver. Note that the DSP buffers can go as > large as 4096. Note that the DSP buffer size (not the audio buffer size) > affects the filter shape.
Ah. I thought they were the same parameter. So they have to be set in different places? I need to go back and look then. > You are correct that multiples of the driver > could be used in the audio setting and it will work. But you'd have to ask > yourself...why? ;) No, I am not asking myself "why" because I don't know. (I have guesses and suspicions but I do not claim knowledge.) I am asking *you* if it makes a difference because you are the official software guru and can tell me whether or not it makes a difference. I also am asking what the preferred setting should be. So it sounds to me like the DSP buffer should be a multiple of the audio buffer and that the audio buffer should be as large as possible. OTOH, smaller buffer sizes mean lower latency but probably higher CPU utilization due to buffer processing. Latency might be an issue with the various ARQ modes, e.g. AMTOR, PACTOR, packet, etc. (Do you have specific information about the relationship between buffer size and latency?) So, it sounds to me that the following table makes sense: Sample rate Driver buffer audio buffer DSP buffer 48Ksps 1024 1024 1024 96Ksps 2048 2048 2048 192Ksps 2048 2048 4096 Do you agree with these settings? Is there any case where you would use different settings? I get the feeling that, while PowerSDR has a lot of "knobs" for changing things, most (almost all?) of the time these will be left alone at some optimum setting. I haven't seen a listing of these things in one place, maybe in one of the knowledge center articles I missed. If it is all written down somewhere and I missed then I apologize for wasting everyone's time. Thanks Eric. 73 de Brian, WB6RQN/J79BPL _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
