Hello and thanks for the answers so far.
I have to say that I dont´t use windows at all. I´m using arch linux. So every windows solution don´t work.
Even in bios I have 51°C at a room temperature between 25-26°C. I testet in bios full speed of fans and the temperature
was 50°C anyway.
About mounting: I´m sure that I dint´t anything wrong, I removed the sticker and spreaded the termal paste thinn on the whole
cpu. The mounting of the cooler with scythe mugen system should be safe, there is imho no option to make a mistake.
I have to say that the 3800xt is takted very high by default. (3,9 GHz and 4,7 under boost)
I tested disable the PBO and that improved the temperatures under load. But it coasts 10% performance and then the
3800xt is just so strong as the 3700x. :-(