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Whenever I render a picture above 16 samplings with Cycles, my laptop crashes in 5-20 seconds.

Is there a way I can manually make the render time longer while not affecting the quality of the render, so it doesn't get my laptop so hot it self-crashes to not melt itself? (I'm willing to use Add-Ons and, if there is a denoiser that could make a render with 16 samplings look like a render with 128 or 64 samplings that's okay for me as well.)

I live in a very poor country and can't afford a decent PC/laptop. Maximum I can afford is something below 50$ (Which would hurt my wallet quite a lot).

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    $\begingroup$ Well I mean, I live in a very poor country and can't afford anything better than this. $\endgroup$
    – stern38
    Commented May 6, 2021 at 20:42
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    $\begingroup$ The best thing I could buy right now is a 10-50$ laptop (If something like that even exists). $\endgroup$
    – stern38
    Commented May 6, 2021 at 20:44
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    $\begingroup$ None of the answers really solves the root of the problem. Ideally you should (carefully) try blowing out as much dust from the laptop if you can since it shouldn't really be overheating in the first place. You could also try a laptop cooling pad which would be relatively cheap. At any rate, just limiting the number of threads, particularly on a single/dual core laptop may not be a great help. On both Windows and Linux it is possible to set a CPU governor/power profile to restrict the CPU from running at full power at the cost of speed which would solve the problem in other applications too $\endgroup$
    – James
    Commented May 7, 2021 at 15:58
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    $\begingroup$ @James Answers should go in the Answers section. $\endgroup$
    – pipe
    Commented May 7, 2021 at 15:59
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    $\begingroup$ Just to check. Is your laptop full of dust? A cheap laptop is expected to be slow, but not to overheat. If it's old simply cleaning the dust out of the fans may help reduce overheating $\endgroup$
    – Richard Tingle
    Commented May 7, 2021 at 21:33

4 Answers 4

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Here is a related SuperUser post.

In Blender, you can lower the number of threads by going to Render Properties -> Performance.

enter image description here

Change from auto-detect and lower the number of threads.

I lowered mine to 2 and started a CPU render and it does appear to split the compute load pretty evenly among the processor cores, so one part of the chip won't necessarily be hotter than the other and it should prevent an overheat.

enter image description here

(This PC runs pretty hot.) :)

It's also worth quickly noting that denoising is a processor intensive task in itself, so it may not be a solution.

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Additional to the other answers, you've also asked for a denoiser - I don't know if you've already tried the Denoise node in the Compositor, it's quite good. Usually you're supposed to turn on View Layer Properties > Passes > Denoising Data with it, but testing this I couldn't see much of a difference. So to use it, go to the Compositor, press Shift+A to Add > Filter > Denoise and plug it between Render Layers and Composite.

Here an example image with node setup: enter image description here

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  • $\begingroup$ Curious, is this a photo or a render? $\endgroup$
    – Hashim Aziz
    Commented May 9, 2021 at 3:26
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    $\begingroup$ @HashimAziz It's a render... that's why the image on the left is noisy without the Denoise Node. $\endgroup$
    – Gordon Brinkmann
    Commented May 9, 2021 at 8:00
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Besides Allen's answer, which is correct, you could also try to lower down memory consumption (which is called "memory cache limit") in the blender references.

enter image description here

Another try worth might be to denoise in a 2nd step...

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If there's ever a non-built-in way to do this (luckly Blender has it), you can change the CPU affinity in Task Manager details view.

Affinity context menu

Affinity dialog

Threads auto detected in Blender: 16

Threads autodetected in Blender

Cores actually used:

Cores actually used

Also, if overheating is caused by Turbo Boost feature, you can prevent that by setting the maximum CPU usage to 99% in the power options.

Prevent turbo boost

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