GPU in every game always 100% (GTX 1080)?

Since I rebuilt my computer for a new purchase, I have performance problems with my GPU.

Current specs:
Core i9-9900k
https://www.alternate.de/Patriot/DIMM-32-GB-DDR4-3200-Kit-Arbeitsspeicher/html/product/1311695?
Gainward GTX 1080 Phoenix
Crucial M.2 500 GB
Power adapter 650 watts
Dell TFT 1440p 144Hz Display Port G-Sync

It just runs in every game except Minecraft with 100% load. Even in the menu of Rocket Leauge. So before with the i7-5820k there were 40% and ingame 60% and now always 100%.
In the desktop, it drops directly to 1-4% Therefore, there can be no general error.
Does anyone have a meaningful idea? Have already identified Game DVR via regedit, current driver is on it, NVidia Game Overlay is off.
I just noticed that it is now even jerky when I'm shot down Quake Champions

This is normal if it is in full load the higher the better the more fps you have to the 5820k already older and even faster at the limit than your current cpu so you do not need to worry.

But the new CPU is the problem because it worked before

Did you reinstall Windows?

So here to protect people from getting more misinformation and guesses out. (who has read the question, could learn that the computer was reinstalled "my computer has set up new")
I found the source of the problem.
G-Sync!
The moment I issue G-Sync, I only have 60% last on the Rocket Leauge - as an example. Well stupid, er, pity… What I have now bought a 200 euro more expensive monitor (annoyed) …

I have no problem?