Asus AC58U help please.

[Mahbub]

I have Asus AC58U and in the specification section under MIMO subheading it says

 

MIMO technology
2.4 GHz 2 x 2
5 GHz 2 x 2

 

Does this mean it can put out 4 simultaneous data streams (two 2.5ghz and two 5ghz) at once, or this means it can put out two simultaneous data streams at once (two 2.4ghz at once OR two 5ghz at once).

 

In short is Asus AC58U a 4 device MU-MIMO or a 2 device MU-MIMO?