Question / Help ELI5: Why are hardware encoders (NVENC and Quick Sync) not as accurate as normal x264 encoding?

[jdnkr]

I was just wondering what the technical reasons are.

 

[Mroczny_Gustaw]

because they are designed for speed not quality and both targeted at x264 ultrafast quality
but yea, looking at the growing speed of qsv and nvenc in latest hardware there seems to be a lot of space now to convert this speed into quality by adding visual optimisations. not likely to happen soon tho if at all considering they are both big fat lazy corporations

 

[jdnkr]

because they are designed for speed not quality and both targeted at x264 ultrafast quality
but yea, looking at the growing speed of qsv and nvenc in latest hardware there seems to be a lot of space now to convert this speed into quality by adding visual optimisations. not likely to happen soon tho if at all considering they are both big fat lazy corporations

ok, thanks for your answer. If NVENC is capable of encoding at 400 fps via ffmpeg it can't be that hard to sacrifice some of that speed for quality.

 

[Suslik V]

The cost and efficiency. Manufacturer decides what it's product able to do. OBS Studio can't convert speed of the hw based codec into quality.