I recently bought a Mi Box mainly to watch online videos but also to play games. I knew that it couldn't play the games that Shield can play but I didn't care because there are other interesting games in the PlayStore like GTA San Andreas, Virtua Tennis and Max Payne.
My Smartphone, a S3 Neo, can play those games, so I assumed that the Mi Box also could (the S3 Neo has a 1.4 GHz processor and 1.5 GB of ram, the Mi Box has a 2GHz processor and 2 GB of ram). To my surprise, none of these games are playable on the Mi Box.
How is it possible that the Mi Box can't play games that a theoretically inferior device can play?
The number of cores and the frequency of the CPU is only one of multiple factors that determine the performance. In playing games GPU is much more relevant, for example. The Mi Box is a budget streaming box, that also happens to play a few games. I had very good results with emulators, but I never bought it expecting to use it as a gaming device, the chipset it's just not designed for it. Also, depending on the Android version, I think that a core might be shut off altogether. Lower power consumption and thermals are a bigger priority here.