First..
Thanks for the praise...
The Card is a Asus 980 Ti 20th Aniversary Gold Edition. And i have remove all Limits!
The ASICS is 79,9%
The Voltages are very diffrent. GPU Tweak shows realy more than all other.
The OC Panel ( Rampage V Extreme) shows a Voltage (under Load!!) between 1,58 and 1,61V. Next run i try a multimeter.
The GPU Tweak window is a evidence, to show it is not subzero!
The Cooling is realy easy: We have Winter in Germany! And a Big Radiator stands outside. Watertemp are 0 - 2 degrees. The System works with three Pumps.