SYN_DerHesse70 wrote:I'm running a Nvidia GTX770 4GB with always latest driver. ...
I'm likely in minority opinion here, but upgrading to latest driver is not always a good idea, especially with older GPU. And yes, the 770 is now an old GPU. Do not get me wrong, I also prefer to use my hardware to its full potential over several years.
This is my just my opinion/thinking here, but consider that nvidia is spending the vast majority of development time on their latest technology and driver optimization for the newest cards. How much time do you think they actually spend making sure the latest drivers are going to be an improvement for older cards?
Yes, most of the last generation cards have the same or similar architecture so new drivers may benefit, but what about significant changes between generations of GPU? It is almost 4 years since the 770 was released.
I strongly suspect that the latest nvidia drivers are not tested for optimization on a 770, other than making sure it still renders when powered up. If you dig online perhaps you can find out which older driver is the most stable for 770 and gives expected render results.