[Discuss-gnuradio] Re: UHD:SingleUSRP and buffer allocation, policy

[Andrew Ge]

 Marcus,

Would you post your flow graph? Also, did you use TUN/TAP?


Andrew


On Mon, Oct 18, 2010 at 08:37:33PM -0400, Marcus D. Leech wrote:

> >  I've noticed latency issues with one of the applications I'm working on.
> >  Latencies of up to tens of seconds
> >     have been observed, which I tried to combat by specifying
> >  recv_buff_size in the parameter list.
> >  
> >  Right now, I'm running with 4096 bytes, which at 400Ksps, gives me a
> >  roughly 1 second latency between
> >     input and output (where output is both an audio sink, and a couple of
> >  different file sinks as well as a
> >     scopesink2, and an FFT sink).  But increasing it beyond 4096 bytes
> >  causes the latency to go up very
> >     quickly, and if I drop it to 1024 bytes, I start seeing over-runs.  If
> >  you do the math, however, 4096 bytes is
> >     nowhere near 1 second worth of buffer.  One second is 1.6Mbytes
> >  (400Ksps x 4bytes per sample).