I have found out some info on the nVidia video encoding. The NVENC encoders in the later nVidia cards are hardware encoding engines, and they are beasts. The GTX1060 uses the GP106 chip - it has 1 of these engines. The GTX1070, 1080 and 1080i uses the GP104 chip and it has 2 NVENC engines. If you get a Titan with the GP100 chip - you get 3!
When I say they are beasts, on the Pascal cards, they can render H.264 or H.265 to 8K. How fast are they? I believe one NVENC engine can render 1080P H.264 at the high quality setting at about 350 frames/sec.
The problem is keeping these beasts fed. So with the Quadro chips, you can run 9 video streams to try and keep two of these engines busy.
Now nVidia seems to be really strict about the rendering license with NVENC and so for non-quadro cards, you can only run 2 streams. When I say they are really strict, NVENC drivers are only available using the closed source nVidia software and will never be open source. And get this - no matter how many GTX1080's you have, you only get 2 streams. If you have one Quadro that can manage 9 streams and 3 GTX1080 cards, you get 9+2=11 streams!
Ok - so how fast are the consumer cards anyway?
I downloaded the open source MediaCoder package as it has NVENC in it and rendered Dave's 2 minute video. On my slow Phenom II pc with the GTX1080 graphics, it was just under 1 minute for both H264 and H265 encoding with the CPU running at 100%. MediaCoder is far more efficient then the Magix codecs and here are the render times I believe you can get on a faster PC with a 1080 card:
H.264: 20 to 25 seconds for the 2 minute video
H.265: 30 seconds for the 2 minute video
By the way, I also tried CUDA rendering from MediaCoder and it is much more fragile and slower. I never actually finished a render. NVENC kills it for both speed and robustness.
Now on my PC, the Vegas 15 rendering is a sadder story. With the slow processor, it takes me 3 minutes to render Dave's video with the Magix NVENC codecs. Dave on his dual Xeons can get down towards 1 minute.
Definitely, the Magix encoders like to take their time. So are we stuck with that?
No, you can run Vegas with other encoders.
With Avisynth, you can render out of Vegas to a file that is actually a Avisynth stream. Nothing actually touches the hard drive at all. The output of the stream can go to the MeGUI transcoder or MediaCoder and you can directly call the NVENC encoders from there. The format you pick to render out of Vegas is usually the Video for Windows DV format or YUV format that generates about 10G per minute of video, but that 10G is just streamed through to the NVENC encoder.
I cannot tell you how fast Vegas is at outputting the YUV format as I haven't set up an Avisynth stream, and I have a 5 year old WD Blue as the drive. Just writing the 22G YUV AVI file to the drive takes about 6 minutes.
If this method did work well, you can probably use Vegas 14 instead of Vegas 15 if you like 14 better. Both have the Video for Windows codecs.
I did see that for NVENC rendering, the Pascal Quadro's can do 9 streams of H.264 1080P high quality frames simultaneously or 21 streams of the Highest quantity of frames. For consumer GPU's, NVENC limits it to just 2 streams. Sounds like nVidia has crippled the non-Quadro Pascal based cards like the GTX 10X0 series.
I know someone who I think has hacked this...
It could work, but nVidia are really keen to protect their licensing. I can't help feeling that the closed source NVENC software with do a thorough job determining the type of card and probably will not be fooled by a hacked card.
The 2 stream restriction is in the nVida NVENC software on the PC and not in the card. It does look like the non-Quadro card has everything it needs to run the same number of streams as the Quadro. If the hack works, then