GPU usage drops from 98% to 30% while gaming

[Matze2570]

Hello.I recently build a new PC but since the first day there was a problem.First it all started fine.High FPS and no stutter.But then I saw that my GPU usage was dropping for like 15 seconds to 30% which led to stutter and fps drops.My system is a 1050ti and a AMD Fx-8350 CPU on a Asus M5A78L/USB3 motheboard.I have 16gb ddr3 RAM.The temperature on my gpu is in the 30-40 degree zone so I think there is a bottleneck but I dont know what is is.I hope that someone here can help me

[Bombastinator]

46 minutes ago, Matze2570 said:

Hello.I recently build a new PC but since the first day there was a problem.First it all started fine.High FPS and no stutter.But then I saw that my GPU usage was dropping for like 15 seconds to 30% which led to stutter and fps drops.My system is a 1050ti and a AMD Fx-8350 CPU on a Asus M5A78L/USB3 motheboard.I have 16gb ddr3 RAM.The temperature on my gpu is in the 30-40 degree zone so I think there is a bottleneck but I dont know what is is.I hope that someone here can help me

Build may be new but the design of that CPU is old.  Not the only fx cpu I’ve seen here lately showing inexplicable  weirdnesses with GPU stuff.  Makes me wonder about newest drivers and support for that CPU.  I got no answers though   

One previous poster was talking about PSU aging.  Not sure if that’s applicable if it’s a new build. 
You haven’t mentioned which GPU so it’s hard to determine if there is a bottleneck.  It’s reasonable that an old design chip like that could bottleneck a newer gpu.