Stream is Lagging my Game

Solution
if you want to change the CPU only, you can get a i7 4790K, but if you want to get new mobo too, you could get a i7 6700k + Z170 mobo chipset and DDR4.


streaming on an older I5 processor isn't usually a very good idea due to it only having 4 physical cores and it having to run OBS usually twitch chat and the game at the same time this is more than likely the cause of your cpu running at 100% also you may want 16GB of ram to stream on.
 



What would an appropriate processor be?
 


for Streamers its recommended to have at least a Quad core hyper treaded processor such as the I7-4690 maybe even the I7-6700k depending on how much you are willing to spend.
 


If I were to buy 8 more Gigs of RAM do you think that will help at all?
 


No, not necessarily. Streaming is a CPU bound task. Try monitoring your memory usage with Afterburner/Riva tuner.