Re: [Discuss-gnuradio] Peak Hold in FFT display causing UI problems

[Josh Blum]

Peak hold is essentially doubling the number of vertexes to draw. If you 
double the number of bins, do you get the same behavior?

You may increase performance by dropping the frame rate to lowering the 
number of bins.

-Josh

On 10/12/2010 01:31 PM, Marcus D. Leech wrote:
> I have an Atom D-510 running Fedora 12, and the latest UHD+GnuRadio (as
> of this morning).
>
> I've noticed that if I turn on "Peak Hold" in the FFT display, the
> entire input side of the GUI becomes
>    unresponsive to input, even for low input bandwidths, where the CPU
> usage is quite low.
>
> Anyone else seen this?
>
> I can easily reproduce this with a simple:
>
> UHD:Single-USRP source ------>  FFT Sink (Update rate 5, Averaging on,
> Peak Hold on)
>
> It doesn't seem to depend on input bandwidth--even as low as 250KHz
> input bandwidth, setting Peak Hold
>    causes the GUI to become unresponsive (although the FFT display
> continues to update).