I use Blender basically for rendering. and often I need to continue working in Blender (modelling - Graphics, CAD) while Blender is rendering.

My assumption is that after blender renders it does not release the memory used, is this true?

Should I close Blender after every render to release the memory?

Any comment, clue will be great.

  • $\begingroup$ Are you rendering with CPU or GPU? $\endgroup$ Commented Dec 4, 2014 at 15:15
  • $\begingroup$ OSX has a program called Activity Monitor and Windows has the task manager. Not sure about Linux. You can use them to monitor how much RAM is being used and whether or not it's being freed. $\endgroup$ Commented Dec 4, 2014 at 16:30
  • $\begingroup$ I'm not sure if it releases it to the OS, but I'm pretty sure it releases it to the rest of the program or at least future renders since multiple renders does not cause runaway memory leaks. I've certainly never bothered to close the program after a render. $\endgroup$
    – Weaver
    Commented Dec 4, 2014 at 23:16

1 Answer 1


Certain things like image textures are cached after a render, so they don't have to loaded from disk if you render again. That can be disabled in the Render Properties panel(But i wouldn't recommend it unless you are really low on RAM):

enter image description here

As previously mentioned, after a rendering, the system memory usage is definitely higher, but there is no runaway memory leaks, so you can just keep rendering again and again without having to worry about Blender running out of memory.

For the GPU renderer, data on the GPU RAM are freed as soon as the render is done.

"Free RAM is wasted RAM". As long as your system has enough RAM that it's not swapping to disk, I wouldn't worry too much about it.


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