I have a gtx 1070 and an i5 7500, lately I have been losing frames and reaching 100% usage on my cpu. My temps never really go above 50C on my CPU and the games that I have so far found that do this is Rainbow Six Siege and Overwatch. I have also checked my task manager and don't have anything thats taking up too much usage
https://imgur.com/a/RAC7Sr3 <---- task manager screenshot
https://imgur.com/a/RAC7Sr3 <---- task manager screenshot