Question FPS dropping when components not at 100%

[Adde21 30]

Ok, so this is a problem i could’t really find anywhere online so I’ll ask about it here. I usually play Overwatch, and I often get a pretty high FPS (~240) but in team fights it drops and goes up and down rapidly from 150 to 110, which is really annoying when playing on 144hz. And when I check my system performance my parts aren’t even running at 100%. I have tried giving Overwatch higher priority in task manager and such, yet it isn’t working

Specs:
RTX 2070
i7-7700K unlocked @ 4.20Ghz (not overclocked)
16GB DDR4 RAM @ 3000mhz
1920x1080p 144hz Monitor
Windows 10 64-bit
Game located on an ssd with windows installed on it, 500gb ssd with 100gb empty space left
EDIT: PSU:

https://imgur.com/a/VDkADu9

View: https://imgur.com/a/VDkADu9


My pc shouldn’t have a problem with those specs (or so I think) and I really have no clue on what to do.
Any help?

 

[rgd1101]

and the temp? make and model of the psu?
and nothing running at 100%? cpu/gpu/ram/ssd usage?

 

[Adde21 30]

and the temp? make and model of the psu?
and nothing running at 100%? cpu/gpu/ram/ssd usage?

Hi! sorry for late reply, my internet stopped working. I can show a picture of the specifics of my psu which I will add to the main post. Using Core Temp I found that the highest temperature was 67 degrees
Also, with "nothing running at 100%" I mean that nothing that is viewable in the task manager is running at 100%. CPU says it is running at about 60%, and graphics card around 20, which doesn't make sense when I am lagging.

 

[rgd1101]

get a better psu

 

[Adde21 30]

get a better psu

Could you be more specific? What am I looking for? A higher watt on the psu? If so, how much do you recommend, as most PSU I can find online have around 500W