POV-Ray : Newsgroups : povray.windows : Not using all CPU : Re: Not using all CPU Server Time
25 Sep 2021 04:44:22 EDT (-0400)
  Re: Not using all CPU  
From: Le Forgeron
Date: 13 Jan 2021 15:25:03
Message: <5fff571f$1@news.povray.org>
Le 13/01/2021 à 20:53, Mike Horvath a écrit :
> On 1/13/2021 12:09 PM, Alain Martel wrote:
>> What can make your CPU time go lower could be thermal throttling. This
>> can happen if there is to much dust in the heat sink of the CPU. It
>> should be cleaned at least once a year, more if you are in a dusty
>> environment.
> 
> The PC is virtually brand new and I just peeked inside the case a few
> weeks ago. It is clean.
> 
> 

Did the render take enough time ?
What is the size of the image, compared to the blocksize (+BS setting,
default is 32, IIRC)
So a picture of 256 x 256 is made of only 64 blocks, and they are not
evenly distributed, at the end it is always some late single block which
is blocking every one else.
64 blocks to render on a wallpaper, 12 cores remove 12 blocks,
52 blocks to render on a wallpaper, 12 cores remove 12 blocks,
40 blocks to render on a wallpaper, 11 cores remove 11 blocks, one core
is late.
29 blocks to render on a wallpaper, 10 cores remove 10 blocks, two cores
are late.
19 blocks to render on a wallpaper, 12 cores remove 12 blocks,
7 blocks to render on a wallpaper, 5 cores are idle, 4 cores remove 4
blocks,
3 blocks to render on a wallpaper...


Did you try to run the benchmark ?


How is the temperature censor of the CPU as the render progresses ?

Is it a laptop in economy mode ?

Is there some energy management in use ?

i5 10400 is reported as 6 cores, 12 threads, base frequency 2.9, max
turbo at 4.3 (but turbo is out of question with povray, it is a mode
when only a single core is used)

TDP is 65 W, I do not know how much that is for a 14nm. (hence my
question about temperature above)

Also, povray enjoy floating point operation everywhere, so it might
trigger bottleneck on the execution of threads (2) over single true
core(1). I do not know the cache size of the CPU per core either.

The graphic chip is also embedded, I do not know if it can have an impact.


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.