When using the Epic UE4 example Epic Marketplace (free) Meerkat Demo, converted to Unreal Engine 5 Early Access.
The Static Meshes are converted to Nanite and over 25% speed improvement occur.
If I build and launch the Meerkat Demo for Windows, there is a 40% increase in speed due to Nanite.
This can be seen in Windows Task manager where the GPU 3D driver works at over 70%.
In the Valley of the Ancient the 3D driver and the Shared memory is not used.
This results in a low FPS. I believe this is because the Valley of the Ancient
uses its own old drivers and not those of Unreal Engine 5 Early Access like the Meerkat Demo.
This is the reason why the command r.nanite 0 switches off nanite and appears to speed up the FPS. I believe it it the old C++ drivers from an old beta version of UE5 causing the problem
The large size of the Valley of the Ancient demo prevents export or extraction of the content to run with the compiled UE5EA