CPU usage 100%, can't find out why

[sonicwither]

Hey, so prior to yesterday, my computer was running fine when I played games. GTA was around 80% and Fortnite was maybe 50% or something like that. Fortnite started lagging for some reason, so I checked task manager and my cpu was running at 100%. I ran GTA later and that was at 90% so I cant tell if it is a game problem or a CPU problem. I just did a computer scan and 0 threats were found.

Specs: i5-660K
RX 480 Strix
Asus z170-e
16 Gbs RAM

Anything else needed please let me know. Thank you for your help.

 

[Supahos]

Check both cpu temps and speed while gaming see if it's slowing down for some reason which is increasing your useage, or if it's overheating and slowing down to keep from hurting itself

 

[yugithedestiny2030]

1. Open Task Manager
2. Go to Performance tab
3. Choose CPU on the left pane
4. Open Resource Monitor
5. Sort by CPU to pinpoint the source