I hope this is correct,

Note 4 - SD625 (14nm, Global) or MTK Helio X20 (20nm, China)

SD625 more power efficient and less heat but MTK processing more powerful and claims to be efficient as well.

Redmi 4X for here is using SD435 (28nm) less powerful than both above.

Redmi 4A is using SD425 (28nm), less powerful than SD435.

Xiaomi did a trade off to pair SD625 into Note 4 with newer design and spec in getting costlier SD650 but older tech in Note 3.

See if the future Note 5 will pair with SD660 but the price is going to be near to 1K mark, time will tell.

P.S. Thanks for the pointed mistakes.

Lemme help you a lil bit.

For Original Malaysia Set, only have Redmi Note 4 (with "global version" on the box). This one comes with SD625.

For imported set,
1) Redmi Note 4 - Mediatek Helio x20
2) Redmi Note 4 global version (similar box with malaysian unit) - SD625
3) Redmi Note 4x - SD625

Man, they sure messed up alot with the description.

I see no difference between both. In fact i have replaced one Redmi Note 4 global lcd with Note 4x lcd and it works well. I think better you buy Malaysian Unit since the price is around the same also.