[hpsdr] KISS Konsole on Ubuntu 14.04

[Hermann]

Hi Jae,

congrats to your KISS-Linux port! Great to hear that.

Regarding the use of cuFFT, I did this for the SharpDSP package (at least
for some part of it) a couple of years ago (on Windows). Just replacing the
FFTW lib with cuFFT though might not be the most efficient way using CUDA.
During the path through the SharpDSP package you need to copy the data back
and forth between CPU and GPU memory. Although this is now much more
efficient with the new CUDA -  I did this with CUDA V2.x - there would
still be a high overhead using some CPU cycles which eventually will
destroy the advantage of cuFFT, if there is any at FFT-bin sizes below, say
256 k or even bigger. The way to go is minimizing copying of data between
CPU and GPU memory. As a consequence some of the computational demanding
algorithms (esp. the NR and ANF algs) should be parallelized to run on the
CUDA cores.

73, Hermann
DL3HVH


On Mon, Sep 1, 2014 at 12:54 AM, Jae Stutzman <k5jae at stutzman.net> wrote:

> ***** High Performance Software Defined Radio Discussion List *****
>
>
> On a whim, I thought I might try the Jetson TK1 board with mono/kiss
> konsole. After working out the dependencies, it appears to run OK (I
> haven't transmitted yet). Anything beyond 96000 sample rate will give audio
> distortion on the receive. If I choose 192000 and then select NR, it really
> goes off the rails. Keep in mind that this is completely running within the
> ARM hard float CPU, which is using the original libfftw3 FFT library.
> Utilizing a CUDA optimized FFT library would probably give a lot more
> headroom. Both the spectrum and waterfall displays are ok with some slight
> hiccup that correspond to audio blips.
>
>
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