Mac Pro (2013- black can) and non mac monitor?
Given no detail on the Samsung display, it seems like you should be able to. Thunderbolt ports can handle Displayport connections. The tech specs for the machine claim 3x5k, so a single 4k should be fine. You'll need a Mini DisplayPort to DisplayPort cable.

Read about Single Stream (SST) and Multi Stream (MST) displays here: Using 4K displays and Ultra HD TVs with your Mac