1080ti unstable performance and low fps?

[benjamin.hughes91]

recently built an x99 system with 16gb of ram a strix 1080ti and a 5820k and using a 1080p 60hz monitor till i can afford a 1440p monitor and i set it all up did my oc to 4.4ghz and a small overclock on the gpu installed BF1 & Doom and im getting some questionable performance so BF1 on ultra in single player fluctuates anywhere from 140-185 depending on whats happening and MP is worse going anywhere from 112-180 normally sitting around 130ish even dropping to 92 for half a second at one point @ 1080p Doom runs around 140-190 ish in firefights and rock solid at 200fps when just exploring the map so Control panel says Cpu is around 15% while HWmonitor says one core is around 90%
so a few Questions
(a) Should my framerate fluctuate that much
(b) are those FPS readings normal for this setup @ 1080p
(c) If not could the cpu be bottlenecking because of the resolution?

 

[COLGeek]

MERGED QUESTION
Question from benjamin.hughes91 : "1080ti unstable performance and low fps?"

recently built an x99 system with 16gb of ram a strix 1080ti and a 5820k and using a 1080p 60hz monitor till i can afford a 1440p monitor and i set it all up did my oc to 4.4ghz and a small overclock on the gpu installed BF1 & Doom and im getting some questionable performance so BF1 on ultra in single player fluctuates anywhere from 140-185 depending on whats happening and MP is worse going anywhere from 112-180 normally sitting around 130ish even dropping to 92 for half a second at one point @ 1080p Doom runs around 140-190 ish in firefights and rock solid at 200fps when just exploring the map so Control panel says Cpu is around 15% while HWmonitor says one core is around 90%
so a few Questions
(a) Should my framerate fluctuate that much
(b) are those FPs readings normal for this setup @ 1080p
(c) If not could the cpu be bottlenecking because of the resolution?