Blender performance issues

So I have been having very serious issues with blender’s performance when it comes to clicking and dragging anything on Blender interface, there is a short lag before what I am dragging moves with the mouse,
Also Eevee takes a very long time when compiling shaders and when doing this the software hangs till the shader compilation is complete.

I am using a system with 16gb ram and a RTX 2080 8gb.

I am not sure why this is happening but I am hoping the devs are aware of these issues and are doing something about it because if this new Blender can only work on very high end machines then that defeats the purpose of Blender being open source.
Old Blender never had all these issues. It ran as smooth as butter on a hot knife.

I use Ue4 as well and I don’t have lag issues at all even for heavy scenes.

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Hi, Blender has problems with viewport performance but it is getting better in 2.83 and even more in 2.90.
What is heavy? If you have 100 4K textures it need some time to load them to the GPU RAM. I have lag to move anything with 3 particle systems and better hardware does not help much.
There is a thread already about: Blender performance issues

Cheers, mib

@mib2berlin Thanks for the info, mate.

I am not sure what the issue is but I would have hoped they considered this lag issue before releasing the 2.8 series. At the moment, it gets frustrating when working, when I click on an object, Blender pauses for like 6 seconds, before highlighing the object. I am wondering if this has to do with them cramming too many features into Blender.
Pardon this dumb question, If it loads to the GPU ram, what happens if the collective size of textures is more than the ram of the GPU? I am wondering if Ue4 uses the same technique.

It load textures in to VRAM if you use EEVEE or material preview.
Cycles as I know of can use system RAM, named “Out of Core” render but it slows down render time.
How many Verts has a heavy scene for you.
I add a scene which is working on my i7 laptop with HD 4000 iGPU on 2.83 Beta.
Check 2.90, too. https://builder.blender.org/download/

Cheers, mib
Argh, 24 MB is to big for the forum: https://pasteall.org/blend/268d748af2574eb69c783b07877ff4eb

I checked the scene. The scene isn’t heavy.
The issue is if I am using eevee and the shader compiles and loads all the textures for the full scene if I solo/isolate an asset, when I switch to normal mode, eevee has to recompile the whole scene all over again. They need to fix that. This makes texturing and working with assets a problem.

Workbench engine does not display high res textures properly if not I would happily use that than eevee. In 3dsmax u could turn off texture display for materials if you wanted.

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Hi, the scene is not heavy but my 8 year old laptop neither and with an integrated GPU.
Eevee is completely different, it is an OpenGL render engine.
Iirc there was huge improvements for Eevee last 2 weeks for 2.90, did you check?

Cheers, mib

Is there a way I can get textures to display in workbench through the shader editor, like turn display for a texture in viewport off and on like 3dsmax. Not a big fan of Eevee at the moment.

2.90 can not be used for production work as its still in development and might get technical issues with a file and work might be lost

I don’t know it that’s what you want, but if you enable the Node Wrangler addon, you can Cmd Shift Click on a node to preview it in the viewport (works in material preview, as well as in the eevee rendered mode).

I don’t think his problems are Blenders known problems with heavy files, what he describes sounds very much like problems specific to his system to me. It sounds like a driver problem or something else.

How long does it take for a scene full of textures of like 4k to load when you isolate an asset and revert to normal mode. I working on a scene with like about over 300 4k textures. In my case about 5-7 mins.
I am using a RTX 2080 and my driver is the latest.

300 4k textures ???
Your gpu memory is not enough

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I don’t think so. Ue4 handles it with no issues. I even have a scene with dynamic lighting and ssgi so gpu memory isn’t the issue.
I have even reduced texture resolution in Blender preferences, I don’t get why shaders have to recompile when you isolate an asset and return to normal mode/view.
The solution is probably to work on each assets in a different file and then link/refernce to the file in a master File. So if you want to edit an asset you go that assets file…I guess.

Hi, if I calculate correctly 300 4K textures are 19 GB!
Blender can use “Out of Core” feature, it use the system RAM if the GPU VRAM is full.
Can you check your system RAM during working on this scene?
This slows down the whole system, especially if the system has to start swapping to disk.

Cheers, mib

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When working with high geometry meshes after sculpting the performance goes bad. If I quad remesh the model with the same number of vertices, I end up with a faster blender. I also noticed that doing an undo on some operations will cause permanent performance problems with blender. Until doing a quad based remesh.

Well in current build of 2.90 it takes around 1,5 minute to add Subdiv modifier to a cylinder with 256 segments. From 258 -> 6144 poly. With bigger meshes (that contains n-gons) it gets much worse.
SubDiv on cone with 256 segments is also very slow.

And sometimes switching visibility of Subdiv in viewports takes the same time. That I found is scene dependent.

In terms of subsurf, you will need to download a build of 2.90 to see a noticeable speedup in that area (as it saw a recent optimization commit which especially benefits meshes with non-quad or non-manifold geometry). 2.83 LTS is unlikely to see that commit anytime soon, if ever.

2.90 also has optimizations in Eevee when it comes to heavy scenes, you can find the daily builds here.

I also have 32 gb ram laptop same issue. If Ue4 can run a scene with over 300 4k textures without any issue and only compilies the shader once when you open the project/file, then Blender needs to re evaluate what has gone wrong. Probably work on making workbench engine more robust and allow for turning texture display of assets off and on in the viewport to improve performance when its needed. Right now, Blender isn’t runing properly on systems with good specs and that is a serious issue.

My issue isn’t neccesarily the time, its the fact that recompiling everytime you switch between Isolate and normal view mode is something the devs should look into and try and resolve it.

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Hi, I want to help OP @melvi.
There is a thread about viewport performance already.
Btw., subdivision does not work for simple mesh like cylinder or cone.
Suzanne need 1/10 second from 970 to 60000 polys.
Anyway, I have no idea how Blender work with 300 4K textures.

Cheers, mib

I know you are trying to help and I really appreciate all the suggestions
My issue is with how the devs are going about these issues without consideration given to smart choices and efficient management since Blender migrated to 2.8 series, performance has taken a huge dive and if I can have issues with the specs of my system, I wonder what people who are trying Blender with lower system requirements are experiencing.

The simple solution is to add an option for Material display in evee/cycles for assets to be turned off and on to allow for better viewport performance if it is needed. I don’t know why they have not thought of this. Shader compilation of every material in the viewport should be something that can be managed by the user
or they make it such that when you Isolate an asset and revert to normal mode, the shader does not recompile.
Personally, I prefer the first one, select a number of objects, in the object properties tab, turn off shader compilation or material display, get better viewport performance as well as reduce shader compilation time, work on your assets. Then when you want to render the whole scene, maybe click a display all material shader button or compile materials for all objects in the scene.

That would be better and Blender would run on many systems without issues… except for the undo part which I am aware they are trying to fix.

I guess we’d need to wait for this one - https://developer.blender.org/T68917

Having hundreds or even thousands of highres textures in a given scene is very common in production, can’t wait to get this one sorted.