[linrad] cpu load benchmarks

[Jeffrey Pawlan <jpawlan@xxxxxxxxxx>]

On Thu, 17 Feb 2005 leif@xxxxxxxxxx wrote:
> Avg      CPU
> 100       12%
>  10       33%
>   3       87%
>   2       96%
>   1      not possible.


I did this experiment using the small computer on my webpage. The graphics card
is a Sapphire Radeon ATI 7000 AGP 32MB.

with 100 or more averages the cpu loading was around 12% as Leif found.
But with averaging set to 1 (disabled) for both the spectrum and the waterfall,
and also the waterfall sized to 75% of the screen area, and the display
resolution set to 1200x1024 I got a cpu loading of only 62%. That was with
96000Hz sampling rate and one channel a/d selected. When I selected 4 channels
the cpu usage went up to 72%.  This is still quite acceptable. My cpu speed is
3.0GHz which is only slightly higher than Leif's 2.66GHz.

Bug found:  If you select a screen resolution of 1200x1024 (mode 13) in the 'S'
menu BEFORE you select the 'U' menu then I got lockup after selecting dsp00. If
I selected 1024x768 (mode 12) then there was no problem setting up the a/d and
d/a dsp choices. Then once 'W' is hit to save the settings, you can go back into
'S' and change the screen resolution to mode 13 and everything works! Leif
believes this may be an interrupt timing conflict problem in either OSS or
svgalib.

73,

Jeffrey Pawlan, WA6KBL

LINRADDARNIL