I am evaluating gnuradio with Ettus USRP X310 and 2xUBX-160 daugterboards, connected via GBit ethernet to a new Lenovo laptop running Win10 and gnuradio 18.104.22.168.
I am testing it with the most basic setup: connecting "RX/TX" back-to-back to "RX2" via straight SMA cable (Remark: I know this is risky and I am careful not to exceed the allowed input power). This simple gnuradio diagram sends out a 10kHz tone at baseband; sample rate is set to 1MS/s and RF carrier 1GHz:
This somewhat works but whenever I change something in the TX path (e.g. the baseband frequency or BB attenuation) it takes way too long for the plots to update: I measured more than 8s(!) from the time I press enter to the moment the plots update. This does not seem to be the case for the RX side (e.g., when I change the RX gain, the plots update relatively quickly).
I also just tested it with QT and WX: It only occurs with QT; with WX the plots update relatively quickly.
Since WX is "deprecated" I would prefer to use QT.
What could be the cause of this? Is there any basic example (that does TX and RX at the same time) I could start with to have a "correct" baseline?