2.79 slow performance on Material drop-down

Anyone having this issue? As soon as I drop-down the materials list everything slows down and become unresponsive until all material previews are created. Or at least that’s what I think its happening.


Do you mean problem occur while you render/viewport render with GPU on Cycles? Or does it also happen in viewport solid view?
Only with material list? Or does it occur in other menus as well? Does it happen in all the scenes?
Does that mean that in Blender 2.78 you were not having that problem? Did you copy previous settings of Blender 2.78 to 2.79? Or do you use clean user settings in Blender 2.79?
What is your OS? What is your GPU?

I never had this issue before and I am trying to narrow down the cause by disabling addons. It is happening just with the material list drop-down as they begin to create those mini preview pictures. I have a powerful computer with 980ti x2 so that is not an issue. I am on OSX 10.11.6. But I doubt that has anything to do with it. After renaming the 2.79 preference folder it seems to work fine so I am almost certain it’s some addon. Will report back as soon as I know more.

I have exactly the same issue. Have you found out what causes this already?

I’ve a issue too with 2.79. The interface seems too low sometimes. In any mode the interface freezes a lot (even en viewport solid view). I have re-instaledd blender and use factory settings. Nothing. Re-install last drivers from Nvidia and nothing. Even older drivers. I forced to open Blender with graphic processor and it still lag a lot.
Very random in fact. Sometimes I can work like 5 or 10min without any lag, but sometimes is insane.

Same here. I’m using 2.79, don’t remember having this problem before.

Same thing here - Windows 10 x64 and Blender 2.79 x64

Could any of you check if selecting “Triple Buffer” under Window Draw Method in User Preferences > System solve the problem?:

If that does not work, choose “full” in the worst case to detect if the behavior changes.
Somewhere I read that in Windows 10 “Automatic” Window Draw Method is not choosing the best option.


I’m not sure if restarting Blender after saving changes is necessary.

Anyway, if so many people are having the problem, someone should report the problem trying to give as much information as possible about how to reproduce the problem.

Sometimes I have also this issue on 2.75a which I use mostly, and in past versions too; it occurs in low memory condition and heavy use of CPU, i.e. some external renderings concurrently running, or other high-demand applications.

It freezes on the building of materials or textures menus, the viewport should not be involved since no changes are performed yet, it has to be due to the display of thumbnails in the menu.


Hi! First, thank you a lot! That solve 90% of the problem. It’s much more better. :smiley: I run Windows 8.1, so it may be not exclusive to Windows 10.

One thing that I saw was the RAM memory. If Window Draw Method is Automatic the memory used by Blender runs like crazy. Jumps from 4GB to 9 or 11GB in seconds doing nothing and comes back after some seconds (in my case). Now it’s way more stable, but i will test it better and if i find something I return here.

Once again, thanks! :yes:

Someone recently create this report (I’m not sure if it’s some user that has participated in this thread).

Is it related to this problem, right? Use that report if you have any interesting information to provide, or if you found a better way to reproduce the problem.

I am seeing this on all my projects right now with 2.79. Very laggy view port and very laggy compiling of material in material preview. Once it starts to act up I close out of the project the reopen. after that, it is okay for a bit but eventually returns to being laggy again.

My redraw is set to automatic. I will change to see what happens.

EDIT: Changing redraw mode did nothing to improve the performance issues.

For those participating in that bug report, please do not forget to provide operating system information, graphic card model and driver version. And much better if you can share an scene and a method/steps to reproduce the problem.


I just updated it.

I am also experiencing long wait times when preview rendering materials. It is taking along time to calculate the updating lights/ importance map portion.

Hi. I have the same issues on 2.79.
Different scenes. Different computers. Different 2.79 Blender Portable packs…
The material icon preview rendering in material tab and node editor select material gives often totally freezes to the blender ui. 30sec to 5 min depending on the number of materials in scene.
Is there any way to dissable the little mat prewiew icons next to material prewiew.
Or knows somebody if these icons will be saved locally? P
The rerendering of these icons happens really often.

I’m still having this issue after getting the latest win10 update, and enabling tripple buffer as suggested.
Anyone figure this one out yet?

To make things even worst, there are usually dozens of duplicates in the image list, and the preview needs to be slowly calculated for each, together with lots of unused images.


Yes exactly, it reloads all the material and texture thumbnails every time I open that drop down. The moment you have a few 2k textures it can take 30s to 1m of blender freezing. Slows down working in the node editor a lot.

I hope that, sooner or later, the developers will come to understand that if two image files have the same filepath and the same name then they are the same image.


Same here… 2.79.1 + win10 … huge slowdown if to open material dropdown list…
Can material preview render be configured to use gpu, not cpu?
Importing a complex 3dsmax scene in blender (2gb size .blend file) with hundreds materials slowdowning blender for tens of minutes, all pc apps keep slow while blenderr create previews.

some news about this? or there are some way to stop blender material preview creation?