Implying UE4 shouldn’t claim to be a game engine sounds a little arrogant with all due respect.
UE4 is multithreading in common/universal problematic areas. For example, recently they implemented animation related multi-threading, an area that benefits everyone.
I think we don’t need to worry on CPU usage simply because DX12 and metal will improve CPU usage within 6months to such an extend that likely most games are going to be GPU bound very soon and it might be preferable to allocate resources on GPU related optimization such as what we’ll get in 4.8 (LOD groups, optimized post process etc).
Every game is different and universal solutions for everything is not always possible. If you have a game with tons of X that eats all your CPU, it might be your job to multithread it for your needs.
At the end of the day, you shouldn’t use the windows CPU usage graph. Use Stat Unit, that’s all you need to look at to start. If you run into CPU usage issues, get the profiler up and start digging.
ARC issues are caused simply because they did not give a **** on performance yet, have a huge open world and lights are running fully in real time. Additionally they customized the render engine with new untested tech.
The game was made in only 6 months and will greately benefit from incoming features in 4.8.
From what I’ve played, I think its pretty clear that the client is GPU bound, not CPU bound so optimizing multi thread is not going to solve anything unless you have a really old CPU. Its likely a drawcall and triangle count issue + new tech stuff, each of which can be improved mostly easily.
This said, I’m pretty sure it will still require a good GPU to run properly simply because they are pushing hard.
The good news is that extreme performance eating big budget games such as ARK or the more reasonable Fortnight drive UE4 optimizations for all of us 