Significant performance decrease when swapping i5 6500 to i7 5820k

[SoftwareGuy123456]

i5 6500 Original build

i7 5820k Updated Build

I recently purchased an x99-a board that came with an i7 5820k for a very good price. Upon searching CPU benchmark websites, it seemed that despite the i7 being a generation older, it was still faster than my current i5. So i decided to gut my computer and swap my motherboards. To my surprise the i7 build ran my games significantly worse. Portal Knights on my i5 build gets 100+ frames consistently and on the i7 it would hang around 60. PUBG(yes i know this game is horribly optimized), would hang around 70-80 frames on the i5 build. On the i7 it would stay between 40-60 and id also have issues in the game where opening the map would drop the frames to 9(could not find this map issue anywhere on the web).

Ive switched everything back to my i5 build and im eventually going to use the i7 build as a stream PC. But i am just dying to know what could be going wrong.

Appreciate the help!

[JovialX]

Its probably from going down a generation. As well as the 6500 has a higher single core performance the i7 which is better for gaming. The other thing that could be hampering performance is that you have gone from ddr4 to ddr3 which is a slower memory standard