Heavy stuttering while source uses high resolution

Have streamed for quite a while now and generally don’t have any major issues, but some months back I’ve noticed that if the game I’m streaming uses a resolution higher than 1600x900 then Broadcaster performance takes a nosedive and ends up on 5 fps. The game is still running smoothly with no fps drops at all though. I have concluded that it’s not a resource issue since the game used for streaming has very low impact on the end result. It all seems to boil down to that magic resolution number on the game.


As shown I try to not go too crazy with my stream settings to ensure that as many viewers as possible can enjoy my streams even on lower bandwidth, but naturally I would like to be able to run the games as pretty as possible on my end.

Anyone out there that might have an idea of what’s going on?