Hi,

I noticed the materialx node's parameter gives faster feedback without promoted than vex vop.
Does not it need to compile at runtime?
What is the backend of Materialx node? C++ or some other thing?

MaterialX is in XML why it is faster i don't know.
What could be is that USD and MaterialX are newer concepts how to handle data and the vex compile was just a speedup of a older data construction (ifd or cross compile in USD).

https://github.com/materialx/MaterialX/blob/main/resources/Materials/Examples/Syntax/NodeGraphs.mtlx [github.com]

I'd assume that if you use MaterialX with Karma CPU it would still need to compile the VEX node graph or code inferred from MaterialX graph as usual