I recently purchased a new PC with AMD Threadripper 1950X, which has 16 cores 32 threads.
I used to use a 8 core machine, so I expected the new PC to render much faster.
But it seems that Blender Internal Render cannot use many threads efficiently.
Rendering with 32 threads is so slow that it’s almost unuseble.
So I tested with various thread counts and I found out that Blender Internal start to slow down with more than
8 - 10 threads (depends on the scene).
Is this a bug? Or is it just how Blender Internal works.
Cycles works fine. More threads, faster the render speed.
The only way to take advantage of 32 threads is by limiting the thread count to 8 threads on a project file
and run 4 instances of blender then hit render on all of them.
I know I should move to Cycles, but I mainly make non photo realistic renders and Blender Internal is much
easier in such cases.
If any one know how to fix the problem or another work arounds, please let me know.