What should I expect from this build?

otherleft

Prominent
Sep 30, 2017
1
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510
I am wondering what could be the problem with my build
Operating System - Windows 10 Home 64-bit
CPU - AMD FX-8370 Vishera 32nm Technology
RAM - 16.0GB Dual-Channel DDR3 803MHz 11-11-11-28
Motherboard - ASUSTeK Computer INC. M5A78L-M/USB3 (AM3R2)
Graphics - 4095MB NVIDIA GeForce GTX 970 ZOTAC International
Monitor - C32F391 Samsung 1920x1080@60Hz
Storage - 2TB Seagate ST2000DX002-2DV164 ATA Device
Games I play; Star Citizen, MWO, PUBG, Tom Clancy's Rainbow six Siege (not as big a problem with Siege). I have a real hard time keeping my FPS above 30 on settings medium or above, even on the lowest settings the frames go up and then down depending on whether or not I am facing the action. This is a real problem when I am trying to line up that kill shot. I know i could have a better monitor with a 144 Hz refresh rate and g-sync, but would that matter since at best I average 50 FPS (fluctuating from 30 to 100). My question is what can i do to get my FPS up over 100 and stay up there somewhere stable?