Came here to say the above and why is the only option a single 8 pin?Without knowing what psu you have... like what grade.... bronze, silver, gold, platinum, titanium, or if its even 80 plus.
And without knowing what cpu you have, along with other peripheals, you may need to change your psu or you may risk transient load spikes on that gpu, which can make your gaming experience really bad.