Hello,
It’s strange, the rendered preview of the viewport is much faster than the material preview in my project.
I’m using big textures (4K)
The rendered preview is done with Cycles GPU (RTX 3080)
When I switch to the material preview (which should be faster) the viewport gets really laggy and unresponsive!
Any ideas to optimize the material preview ?
Thanks
AFAIK material preview uses eevee (and you have to switch to eevee to set for example the viewport samples) and of course the rendered cycles preview can set to 1 sample… you are sure the cycles preview isn’t rendering any further while you are looking at it because eevee does build the complete image before showing it… ??
Thanks for your help!
I went to check the settings for Eevee and I setted up the sampling to very low values.
I also switched off several options to optimize eevee.
Finally I went to the preferencies and I decreased the textures sizes for the viewport.
But all that doen’t change anything.
The viewport is still very slow and unresponsive with the “material preview”. 
In rendered viewport mode with Cycles the scene is very “fluid” and responsive.
I’m using Optix denosing and the scene continue to build but at least the scene is fluid and responsive.
It’s not the case with the material preview.
I almost tried all options linked with viewport optimization in the preferences AND all options that I could turn off in Eevee.
Nothing is working, the material preview mode of the viewport is still laggy and unresponsive.
BUT I found that my screen resolution has an impact!
So if I move blender to a Full-HD screen then it’s much better BUT if I move blender to a 4K screen I get the laggy and unresponsive viewport.
I don’t have this issue with the rendered viewport mode 
Yes 
much more to show on 4K…
Not sure if that’s related, but I’ve seen some people in here lamenting (not meant as something negative) about performance regression in Eevee in the latest Blender versions.
Yeah, Eevee was usably (sorry excuse style) slow after 3.1.2, that’s why I didn’t bother using anything after 3.1.2, the whole point of Eevee is real-timeness, they have it…and then suddenly…they lost it…for features that wait…what feature ? Nothing…
Blender 3.3 is just out…I will check it out soon to see if Eevee is still crippled when I am home.
I only use Cycles. One of the reasons is that I never bothered learning Eevee, but the urge has always been there, since it’s a huge part of Blender. However, the two projects (personal) I started with the intend of using and learning more about Eevee, I stopped, because at some point the viewport & shader editor navigation became so unresponsive that continuing wasn’t fun anymore.
Granted, one part is surely coming from my lack of knowledge how to properly setup Eevee and secondly, they were complex environment scenes, but they were not overly monstrous. The bad performance made me stop and I’m back at Cycles. Both projects used Blender 3.X.
Did you try Blender 3.1.2 ? Eevee is VERY GOOD, almost EXCELLENT in that version.
Ok, just tested Blender 3.3, same setting as 3.1.2…
OMG Eevee is SLOW AS hell !!! There is a very visible but short lag, I don’t have to deal with this…
Going back to 3.1.2…
Wow everything is smooth and real time again !
Hello,
Actually in my case it’s almost the same between 3.3 and 3.1.2.
BUT I’m using very complex shader designed for Cycles.
I think it’s the problem!
I’m guessing that the shaders I’m using are not working very well with Eevee (they are not designed for Eevee) and they make the preview with Eevee very slow.
In addition, I’m using 4K texture on large landscape …
Since I just want to preview the textures in “material preview” to tweak the UVs → Then I created a deviation based on the type of rendering method.
So for the very complex shaders I created two outputs, one for Cycles with the original shaders and one for Eevee with simplified shaders.
And now IT WORKS PERFECTLY! 
