AMD Graphics Card: Radeon R7 M260X
Laptop : HP Elite Book 840G2
Operating System: Windows 10 64bit
Driver version installed: ?
Display Devices: considering purchase of NEC EA275 UHD 3840x2160 @ 60Hz (connect via DP 1.2)
Will this card provide the 3840x2160 resolution @ 60Hz so that I can fully exploit this monitor?
If not, what is the max resolution I can expect @60Hz?
The card is capable of it if connected via DP, but your system manufacturer may be using a customised version. In short, only HP can properly answer this.