Hi. We have bought a B200 board and are having issues simply receiving the samples and would like some support in the matter.
Running the command ./rx_samples_to_file --null --rate 56000000 on a Sony Vaio Z with an I5-3210M running Ubuntu Server 17.10 shows a high CPU usage of ~78%. Is such a high CPU usage expected? Switching terminal windows (ALT + F1 or ALT + F2) is enough to cause an overflow on the Linux host. There is also a high CPU usage on a Windows 10 machine (ThinkPad, i7-4810MQ). Running ./rx_samples_to_file --null --rate 56000000 results in a infinite stream of overflows. Running ./rx_samples_to_file --null --rate 32000000 utilizes 22% CPU and still overflows once in a while. Moving a calculator window around the screen results in overflows. We have tried increasing buffers using --args="recv_frame_size=X, num_recv_frames=Y" However, we haven't been able to increase X to higher values than ~16000 (16384 fails with lots of overflows). The same applies to Y, where 300 fails with an error. The software was compiled in release mode an ran over a USB 3 connection. Thus, for USB transfers using the B200: - On Vaio: Is ~78% CPU usage expected for 56 Msps ? - On Win10: Is it not possible to receive 56 Msps? - On Win10: Is 22% CPU usage expected for 32 Msps? - Is there some limit to recv_frame_size? A value of 16384 fails with infinite overflows. - Is there some way of tuning the framework for lower CPU? We hope you are able to help! _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
