I think it's nvme at something a little faster sata 6 speed dude not sure....I think.. rampage had it too and few other boards did...this oem board i have does not have one though....kinda crappy board...but i know now the x5650 is still good, would be a good clocker on the Sabertooth or UDR3...
don't matter back on z270 and 7700k smokes just about everything prior...unless some still on broadwell or any haswell...saved the 4770k 4790k or like yeah that 5820k stuff like that....that one I thought was soldereddd though...and people deliding soldered stuff anyways....
Ignorant lol...
stuff was originally mostly ever down to known chips that weren't soldered....