We had the same issue. We recently bought a Dual 128 cores Epyc machine.. and the performance is almost half time compare to a Dual Xeon 2699v4. It not make sense. There is some important work to do in Corona render core to get the benefits of this kind of CPU´s. The Xeon 2699v4 has 44 cores, and the Epyc has 256 with more Gigaherz. The time need to be around 8 times faster but the perfomance is less than haft time. Less features and more performance. It the same in the Threadripper WS.
I read all the forums, topics, info. I try to test the corona 12.. There is something in the kernel, Core of the program(Corona Render),that need to be change
