PC General Game Performance Issues

[SirParadox]

So, I've just bought Just Cause 3, and it's quite fun, but there's one problem, the performance. My PC specs are as follows:

 

CPU: Intel® Core i5-4570 CPU @ 3.20GHz

GPU1: Sapphire Radeon R9 290 Tri-X OC

GPU2: Sapphire Radeon R9 290 Tri-X OC

RAM: 16GB

OS: Windows 10 64-Bit (build 10240)

DISPLAY RESOLUTION: 1080p

 

I've talked to people who have a Sapphire R9 280 who can run this game on high 1080p, 70~ FPS. With the same settings, my game will occasionally run at 70~ fps, but mostly 50-60 and can drop to 30. I also have the latest drivers. I know the game doesn't run in CrossFire yet, but despite all the settings I change, the performance is the same. Any help?

 

P.S. Here is a system summary from dxdiag:

 

dxdiag.txt

[Fluxx]

I'm guessing it's the CPU, my usage sets at around 70-90% on my 6600K @ 4.5Ghz but I haven't got any framerate drops yet.

[SirParadox]

I'm guessing it's the CPU, my usage sets at around 70-90% on my 6600K @ 4.5Ghz but I haven't got any framerate drops yet.

Ah. Well, if I were to upgrade my CPU, what would be the best option?

[Fluxx]

Ah. Well, if I were to upgrade my CPU, what would be the best option?

Probably a 4690k.