I'm a newbie here and I coming with a strange problem (for me...).

Just to introduce my config: I use Blender with an i7 CPU (3930K 6-core), a GeForce GTX660Ti, 32Go RAM, and I work with Windows 10 Pro.

I made often simple scenes, the last one are a dozen of gears which turning and that's all, all frames have the same complexity level.

When I render animation with a render time about 2,5 minutes/frame in 4k resolution for example, as long as I used my computer (to surf on Internet or some little things) the render time is stable, BUT if I leave my computer, after some time, the render time slowing down! And the frame use even 5 minutes!!! If I move the mouse, the next frames becomes normal with 2.5 minutes... Strange, no?

All right, all the time saver are off (screen, hd stop, etc...), please have you any idea about that problem? Thanks a lot in advance!!

  • 2
    $\begingroup$ There could be some kind of power saver feature that is preventing your processes from taking up too much CPU $\endgroup$
    – 10 Replies
    Dec 8, 2016 at 11:43
  • $\begingroup$ you could try one of these raymond.cc/blog/… $\endgroup$
    – 10 Replies
    Dec 8, 2016 at 11:44
  • $\begingroup$ Are you rendering on CPU or GPU? $\endgroup$ Dec 8, 2016 at 12:44
  • 1
    $\begingroup$ For Josh: It's only when I use GPU rendring. For 10 Replies: I don't think that's a power saver feature because I desactivated all $\endgroup$
    – ShkYo
    Dec 8, 2016 at 12:45
  • $\begingroup$ Disable any kind of power saving feature or screen saver. $\endgroup$
    – user1853
    Dec 8, 2016 at 14:42

1 Answer 1


I think that as you are using GPU rendering after a while as the image is still roughly the same on your screen, the GPU hibernates/ power saves as it is not being used. That is probably why when you browse the internet it goes back to normal.

I would recommend CPU rendering unless your GPU is O.P. compared to your CPU which i don't think it is.

  • $\begingroup$ Yes why not, but usually with Cycles my GPU renders are 1.5x to 2x faster than my CPU render... Each animation render take around 15 to 20 hours, if I use the CPU, render time will take 30 to 40 hours each! I'll prefer to find a solution against the save power of the GPU... Maybe with a little graphic screensaver? $\endgroup$
    – ShkYo
    Dec 8, 2016 at 13:55
  • $\begingroup$ Then I would maybe play like a YouTube video or something that will constantly keep the screen active and make sure that it is ontop of everything else $\endgroup$
    – Alphex
    Dec 31, 2016 at 10:17

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