Clean blender memory

Hi! how can I clean the memory that blender use? for now the only thing that work for me to clean the memory is to close and open the file, can I find some button or script that know how to clean the memory that blender take?

If you were to clean your RAM of anything Blender related, Blender would immediately crash. Programs can’t run without taking up memory space. What is your end goal here? If you just want to free up RAM, try purging your orphans, using instances instead of duplicates, and using smaller/less texture images :slight_smile:

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No, i want to clean all the extra ram that blender not need…
for example - i have a very big scene, and in the bottom right corner i see that blender take 5GB of memory, so for my test i remove everything from my scene (all the objects, images, etc…), and do a purge for the file and save it, but also after all that the file is still very heavy (around 2.5 GB of memory), but if i revert the file (or close and reopen it), the memory is only around 50MB… so i want to get the 50 MB without closing and opening the file

Blender caches everything so you can have undo and redo. You can delete whatever you want, but as long as it’s in the undo history, it’s still in the RAM. Also, any shaders that are compiled remain cached until you close Blender. You can, if you want, turn your undo steps all the way down, which will help a bit. At the end of the day though, closing Blender is the only way to completely clear the cache.

Note that this isn’t just a Blender thing. Google Chrome, for example, caches tabs, even if you close them. This allows you to immediately reopen them, but it means that you can’t clean up your RAM until you completely quit Chrome. Most programs work like this, the point of RAM is to provide a cache, and it’s generally bad to clear the cache while the program is still open :slight_smile:


I understand that, but its sound weird to me that i dont have any button that allow me to do that if i want…

If you clear the RAM, Blender will close. Conversely, the button to clear the RAM is the close button :wink:

I dont want to clear all the ram of my computer, i just want that blender will remove all the ram that he not need any more (like all the undo…)

You can accomplish this by simply saving and refreshing/re-opening your blend file.

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You can set an “undo memory limit” or turn down the amount of undo steps.
Edit>Preferences>System>Memory & Limits


This subject sure seems to come up a lot, lately… don’t it ?

What operating system?

Windows? Do some work, save it, walk away… Windows will clean it up every so often…???

Forgive me if I’m mistaken, but aren’t textures placed under the graphics card VRAM and not RAM?
RAM is only for system related things such as application instances, as you mentioned.

Even if you don’t have a graphics card ?

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If it was a integrated GPU and not a dedicated one, then yes, it would use RAM over VRAM. However, I assume the OP had a dedicated GPU, as Blender’s requirements require a moderately dedicated GPU as well as one that supports the necessary up-to-date OpenGL drivers.

And yet… I happily render 30 fps videos with an integrated GPU.

Isn’t life strange?

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You’re probably right. One way or another, the only way to clear the RAM is to restart the program, that I know for sure

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Why do you think you have to clean manually anything an application does… Do you want to clean your browser too? Or your Email client or any other app?? Why do users think they could manage RAM better than the app or the OS they use?? Or are you specs so low?
Anyway: If you have unused things and think/notice your computer get’s slower… then in Blender Outliner → Orphaned Data may help you.

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Do you want to clean your browser too?
yes, if its save junks that he not need and he dont clan it so yes…
The blender not need this data, because after I reset the blender he free up the memory

You didn’t answer if you get performance problems or why you are in need of doing this… but maybe i’m just lucky to don’t have to do this ever with my 8GB RAM… (Even my operation system didn’t need a restart since uptime : 11:37:34 up 141 days, 19:02, 6 users, load average: 0,36, 0,37, 0,39 my bad. Using a browser with > 32 tabsand one blender 2.93 and one 3.01 right now. )

yes, I have performance problems, I have very large scene, and i want to see what take a lot of memory, but when I remove stuff I also need to reset blender to see how its effect the memory…