POV-Ray : Newsgroups : povray.beta-test : v3.8 Clean up TODOs. f_superellipsoid() / shadow cache. : Re: v3.8 Clean up TODOs. f_superellipsoid() / shadow cache. Server Time
24 Jun 2021 08:07:08 EDT (-0400)
  Re: v3.8 Clean up TODOs. f_superellipsoid() / shadow cache.  
From: jr
Date: 17 Apr 2020 10:40:01
Message: <web.5e99be1d1e176347827e2b3e0@news.povray.org>
hi,

William F Pokorny <ano### [at] anonymousorg> wrote:
> ...
> Yep, I couldn't let these weird results go...
> ...
> As for why (2) where the raw SDL encoding is winning over an inbuilt
> compiled result. Looked at it with the linux perf profiling tools and it
> looks like when the pow() requests (done internally as exp()s and
> log()s) come at the hardware too fast, some are getting delayed. I see a
> big jump in pow() hardware cycle counts and under them irq and timer
> routines which are not there in the SDL hard coded case. Not sure if
> this 'hold up a minute' by the cpu is to control power or it's the way
> the hardware (an i3) handles too many overlapping pow() requests.
>
> Some better timing data below.
>
> I think going forward in povr ...

if it's any help, I'd be happy to compile 'povr'[*] and run your test scene(s)
on an i5, for comparison; also, can capture session(s) and send transcripts.
(assuming that if I configure + build under /tmp, povr will use installed v3.8
povray.{conf,ini} files)

[*] different configurations, if wanted.


regards, jr.


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