[2020] WARNING: Riot Client Services CPU usage!

I believe we may have pushed out a fix for this issue. Please restart to pull down the latest version. Make sure the RiotClientService.exe is dead prior to starting the game back up again. It seems to have been getting stuck shutting down for a few folks, use task manager to kill it. Once its dead and you launch the game again it should install the latest version with the fix. Let us know if you are still running into this after downloading the latest version.

Game as in VALORANT.exe or RiotClientServices.exe? Which process is using 100%?

If its Valorant.exe then it is a different issue. The issue in this thread was with RiotClientServices.exe. You can reach out to player support, they may have some ideas.

Which process is causing the high CPU usage? RiotClientServices.exe or VALORANT.exe?

I can only help with issues with RiotClientServices.exe. If the high CPU usage is indeed in LeagueClientUxRenderer then it could be related to the new patch. The 10.8 patch was released on the 14/15. I haven't seen any discussion about FPS drops due to LeagueClientUxRenderer CPU utilization with 10.8 but I am also not on the League team so I am not in the loop for a lot of these types of discussion. I think the VALORANT devs in this subreddit wouldn't be able to help either.

My recommendation is to reach out to player support. They may already be aware of the issue and have a workaround. If they do not have a workaround, it is still useful to report so they can have an estimate of how many people are running into the issue. It may help get the issue prioritized over other current issues that are being dealt with.