That looks like a pretty generic cable. Does the mac pro have a specific connection that most PC's do not have? I would just check at a computer store like canada computers.
“If you are neutral in situations of injustice, you have chosen the side of the oppressor. If an elephant has its foot on the tail of a mouse and you say that you are neutral, the mouse will not appreciate your neutrality.” Bishop Desmond Tutu
Sorry, all. I was worried about needing this cable before I actually opened the computer. Once I opened it, I saw that the old graphics card had one. I just swapped the cards and plugged the cable into the new card.