Hi,
So I am using Vegas Pro 15 and found this plugin this week by chance.
Ususally I was using Magix internal "hardware accelerated" codec and was disappointed by it's "perfomance". But even with Voukoder my taskmanager always shows 100% CPU usage and only 10~15% GPU Encoder usage - obviously the rendering time is the same wether I use H/W accelerated profiles or Voukoder or CPU-Processing.
On my secound PC with a Radeon 380, I can use Voukoder with AMDs H/W Encoder with expected performance and nearly 100% GPU Encoder-usage shown in the taskmanager.
I am using the latest Non-Beta-Gameready drivers provided by Nvidia. Turning off wether shadowplay nor Win 10 DVR halped.