Vontar X4
37.77 euros, sale starts in 5 hours in UK. you should get it for 35 euros after the coupons you can apply.
It’ll do pretty much everything except DV
best value box for the performance and features, install CoreELEC on EMMC, it will be pretty blistering
this is a list of boxes with single core python speed measurement
I would love it if you ran the test and gave me some me the result on your S912 hardware, you can find the “CPU BENCHMARK addon” in official kodi repo. install and run and you’ll see a url with the results
more details here
the next best is the TOX3, but they pretty identical and like 8 euros cheaper for the Vontar