# Uhd\_fft not resonding **URL:** \ **Category:** GNU Radio\ **Created:** [December 18, 2014, 7:40pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500 "2014-12-18T19:40:38Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [December 18, 2014, 7:40pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/1 "2014-12-18T19:40:38Z")
I’m using Ubuntu 14.04, UHD\_003.008.00-18-g864f84b5 and GNU Radio 3.7.6 Whenever I start uhd\_fft from a command line, the window opens and starts to plot. After about a second, the window goes into not responding mode, where it greys out and you can’t click anything. Does anyone know what could be causing this behaviour? Is it a local setting of mine? Rich ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 7:56pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/2 "2014-12-18T19:56:00Z")
On 12/18/2014 07:39 PM, Richard B. wrote: > I’m using Ubuntu 14.04, UHD\_003.008.00-18-g864f84b5 and GNU Radio 3.7.6 > > Whenever I start uhd\_fft from a command line, the window opens and > starts to plot. After about a second, the window goes into not > responding mode, where it greys out and you can’t click anything. Does > anyone know what could be causing this behaviour? Is it a local setting > of mine? Are you using Ubuntu’s unity? It might be a GL issue. Try if setting style = nongl will help. M ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:30pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/3 "2014-12-18T20:30:24Z")
See “to enable OpenGL sinks” here: > **[GnuRadio installation](https://sdrblog.wordpress.com/gnuradio-installation/)** > > installing from source First, install all required packages: sudo aptitude install swig build-essential git-core automake libtool python-dev libfftw3-dev libcppunit-dev libusb-dev fort77  sdcc libs… You’ll use “style=nongl”, instead of “style=auto” or “style=gl” On 2014-12-18 14:25, Richard B. wrote: > > > starts to plot. After about a second, the window goes into not > > > > * * * > > > > Discuss-gnuradio mailing list > > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] > > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] Links: ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:35pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/4 "2014-12-18T20:35:19Z")
I don’t know if this matters, but I used the pybombs install method. I am looking for the .conf file, but the only thing in my .gnuradio directory is ~/.gnuradio/prefs/vmcrcbuf\_default\_factory ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:26pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/5 "2014-12-18T20:26:43Z")
Yes I’m using Unity. I forgot to mention my hardware, which is an N210 with WBX daughterboard. I’m not sure how to make the style change like you mentioned. On Thu, Dec 18, 2014 at 10:54 AM, Martin B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:46pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/6 "2014-12-18T20:46:59Z")
I created ~/.gnuradio/config.conf with the following lines in it [wxgui] style=nongl This has not fixed the window not responding issue. Any other ideas? Rich On Thu, Dec 18, 2014 at 11:33 AM, Richard B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:58pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/7 "2014-12-18T20:58:39Z")
When the window greys out, my CPU is only at 45% usage. When I run uhd\_usrp\_probe I get all the device info you would expect to get. The command works as it should. Rich ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 9:25pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/8 "2014-12-18T21:25:41Z")
The key setting that mleech pointed out was setting the fft-rate lower, uhd-fft --fft-rate 5. I suppose the N210 can’t handle the default setting, since my laptop (corei7, 16 gig ram) doesn’t seem to be the bottleneck going by cpu usage and mem usage. On Thu, Dec 18, 2014 at 11:57 AM, Richard B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 8:50pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/9 "2014-12-18T20:50:40Z")
When a window greys out, it typically means you’re using too much CPU. Ron ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [December 18, 2014, 9:33pm UTC](https://www.ruby-forum.com/t/uhd-fft-not-resonding/233500/10 "2014-12-18T21:33:39Z")
The N210 neither knows, nor cares, _what_ is going on on your CPU, nor whether there’s enough CPU for it to send samples to you. To use a physical-world analogy, Niagara Falls neither knows, nor cares, whether the bucket you’re holding at the bottom of it to “capture” it is big enough–it’ll just keep on being Niagara Falls regardless. Also, you’d quoted 45% CPU consumption, which is _total_ consumption, which means that at least _ONE_ CPU was probably totally-pegged. Individual processes don’t automatically occupy multiple CPUs. That’s not how multi-core systems work. The kernel schedules threads across multiple CPUs the best it can. A single process thread can still “starve” for CPU, even if other threads, on other CPUs are “happy”. In this case the thread that was doing your FFT display logic was probably running into CPU limitations–the wxGUI FFT sink (which is what is used by uhd\_fft) isn’t the most efficient. However, on a modern i7 CPU, it should still be able to support 15 updates/second, so I’m guessing that your CPU performance profile is set to something like “power saving” or similar. You’ll have to research how to adjust that on Ubuntu under Unity, since I don’t know myself. On 2014-12-18 15:24, Richard B. wrote: > Rich > [wxgui] > > Yes I’m using Unity. I forgot to mention my hardware, which is an N210 with WBX > daughterboard. > > > responding mode, where it greys out and you can’t click anything. Does > > Discuss-gnuradio mailing list > > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] > > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] Links: