2k vs triple monitor performance

[Sweeds]

which uses more performance? a 2k resolution monitor or 3 1080p monitors?

 

[rgd1101]

2k is 2048 × 1080
3 1080p is 3 x 1920 x 1080

 

[JackNaylorPE]

4k = 3840 x 2160 or 2160p = 8,294,400
3 x 1080p - 5760 x 1080 = 6,220,800

4k requires 33% more oomph to move those extra pixels