[noggin]

Too many variables in play I think to classify anything accurately other than to say Hardware decoding of any codec provides peace of mind and certainty that it will get the job done properly.

...
H264 4:2:2 40Mbs 1080/50i went from unplayable on a quad core Ivy Bridge i5 NUC to playable with YADIF 2x CPU deinterlacing when multithreaded decode arrived.

So that I can take as an answer for my question here too. A core i5 is minimum to achive H264 4:2:2 40Mbs 1080/50i decoding in software or would a core i3 be enough? Mean is a i5 that headroom to have or is it with a i3 and multithreaded decoding in software enough headroom?

Thanks again for all your support.
Regards
Vlaves

All 4 threads (Dual Core with Hyperthreading mean 4 CPUs reported) sit at well over 50% so I think it would be possibly too much for a similar low-power i3. Can't say for certain as I don't have any low-power NUC-style i3 set-ups. However this is 4:2:2 not Hi10.