Hi base-bone,
Sadly, I have no M3 here, and I would like to wait for the studio version this time since the M1 MBP is sufficient, and I currently do not want to replace it.
However, I will ask others on the team who have that option about their experience with the M3. If some negative is given, I will report back.
This can have many reasons. (AFAIK:) Changes in the Nodes lead artists to set the refresh only while the IPR is idle, as the "real" preview of material is checked in the IPR instead. So, the material preview itself is secondary and doesn't slow down the IPR.
This leads to whether this always happens or only when the IPR is active.
Screenshot 2024-03-10 at 2.35.10 PM.jpg
Another question would be, if nothing else in the scene shows that problem and fresh material shows that problem, then this should be checked with tech support.
Anything that needs to be handled by the GPU requires space. I assume nothing new to you, but I write in a forum, so forgive me. This means existing data from a scene needs to be kicked out temporarily.
In the older (XPresso Style) Node editor, you have other Options, such as Auto Refresh.
Sometimes, setting the Preview size too small in the material helps, but I also read that people did not benefit from it, which indicates that it depends on several parts of the whole pipeline.
My personal take, not backed up so far by training material, is that the great optimization in the app is countered by huge Node trees while handling things that could be set up in an image editor first and then merged to a single texture, optimized to the size needed, instead of just having, e.g., 8K texture files for an object that never is prominent in the rendering.
When new external material is added, this is a process of optimization, not just a read action, which can take a moment.
I'm sure I have not covered all, but without a scene file and the same setup as you, I might not be able to answer that. Hence:
It will also be beneficial to check this with tech support just to exclude or include all possibilities.
https://www.maxon.net/en/support-center
All the best