I have a amd 8150 @4.0 ghz that i got 3 years ago. Would i be better off with with a 6700k skylake or a 5820k? or would it matter.
Rendering is done on gpu so it’s does not matter if you just have fast enough cpu. Or did you mean lightmass?
The 6700K has a higher clock speed but fewer cores, in situations where a task is not multi-threaded it will be faster. With Lightmass there will be cases that one or the other will be faster depending on the objects. Each object gets assigned to a single thread so more cores will be able to render more objects at once. However, if an object has a large lightmap then it will take more time to render and the other cores will not be able to help render that object so the higher clock speed would work better in that situation
But as a note, the 5820K uses a socket that you can upgrade even faster, like the 6800K up to the 6950X
yeah for light or other cpu functions.
whish there were atcual benched marked results for ue4 and diffrent processors do you know of any, you did clear up alot though ty 
light mass or any other cpu function not talked about much.
did you check new macbook pro?