As I was quite busy (still I am), did not have time to keep up with the forum.
But I was mentioned and that triggered an email notification which I can’t whithstand. 
You got it almost right, however that rises nowadays a (geo?)political issue, as it makes remember the shape of Hungary in the ancient times and before 1920…
My area is called today simply Hungary, and this area does not match the Carpathian Basin as it was the case before the Trianon peace treaty… It’s not just Transylvania, but also west part of Ukraine, south part of Slovakia, and so on around all the borders.
I’m not hurt anyway, especially reading your kind words
Thank you, I really feel honored.
But I’m definitely not a guru, I just use the trancodings on a daily basis.
There are some input formats I get from clients recorded with their phones maybe: Davinci refuses to work with those, mostly totally, sometimes only the audio track is missing.
So I need to convert…
My camreas record in a format today compatible with the studio version, but I used the free version for years, and I had to convert them too…
When I render out a timeline, it ends up in a prores or similar “high-format” file.
So I need to convert it to .h264 or rarely .h265.
I tried nvenc on nVidia, my laptop has GTX1050Ti, my desktop had GTX1060, later GTX1070, the speed was similar, around 170 Fps. With VAAPI it was slower.
Using the intel GPU with VAAPI was slow again, but I don’t remember the number.
Using the intel GPU via Quicksync is unbeatable, it’s always above 250 Fps, and sometimes near 400 Fps, I guess this depends on input file format as well.
This is with 8th gen CPU and for h624 at fullHD resolution.
So I stick to QSV for transcoding (ffmpeg), nvenc for encoding on laptop from OBS (very easy to set up, and fast enough to efficiently decrease CPU load during a broadcast).
Nvidia supports OpenCL as well.
Yes, intel has OpenCL support too.
There are various implementations though, so different apps work with different OpenCL versions. That’s for me a pain, as Davinci Resolve is quite picky, it doesn’t lik intel’s OpenCL currently available in Linux, and requires the version from AMD in the “pro” drivers.
The Mesa OpenCL does not work 