[Discuss-gnuradio] Running Ubuntu 11.04 AMD64; Getting crazy latency results, about 20ms

[Colby Boyer]

Hi all,

I'm running a duplex system on the USRP1; using UHD drivers (about 1 month old). For the sample rates, I have 640KHz to the USRP and 1MHz from the USRP. The turn around time for a simple amplitude detected signal is approx 20ms, which is crazy high. Btw, I'm measuring the latency (approx) by observing the nitems_written() method for the block that produces samples for the sync.

I'm running UHD and gnuradio with real time threading enabled and giving the gnuradio app a nice of -20. Since this happens before any math occurs, I assume the kernel is lagging on this. Could switching to a modified kernel with realtime improvement patches help?

Thanks,

Colby