Hi list, I have recently begun to see a lot of tx_underrun in my applications. At first I thought it was due to me not setting realtime- scheduling properly (which I did), then I thought it might have something to do with recent fusb_* updates from gnuradio (which it didn't, since I downgraded to svn10527 (I did use svn10537) which used to did work). Then I thought it had something to do with me running to many other processes on the host computer, but that turned out to not make any changes either, since I closed all "unnecessary" processes (including gdm, Xorg and so forth). Then I thought it might have something to do with Dell cheeping out on the usb-2.0 ports, so I tried switching between the four of them between tests, but no luck there either... To check for the underruns I use "~/gnuradio/usrp/host/apps/test_usrp_standard_tx" (I tried it several times both as root and as user) which is reporting ~40 underruns, and a throughput of about 29-30mb/s. On the other hand, when I'm trying "test_usrp_standard_rx" it reports 0 underruns and 32Mb/s throughput. The peculiar thing is that code that is running fine on a Dell latitude e6400 with Ubuntu 8.10 and gnuradio svn10527 isn't running fine on a Dell latitude D630 running Ubuntu 8.10 and gnuradio svn10527. I know the Latitude e6400 should be a more "manly machine", but I think the D630 should be able to handle "test_usrp_standard_tx" should it not? It has done so before at least... I guess my question is, -"Is there anyone who has any clue why I see these underruns, and/or what I can try to make them go away?" Best regards //Mattias K.
on 2009-03-04 19:28
on 2009-03-04 19:39
Hi again, Seems like the answer was coming in as I wrote the answer... My cpu- scaling... BR //Mattias K.