adding NVIDIA GeForce GTX 285 as a second card !

I have a NVIDIA card that cam with my mac pro, then I got the NVIDIA GeForce GTX 285 to use as my main card but I would like to use the NVIDIA as a secondary card I usually have two displays + my cintiq connected. Here's the problem the NVIDIA GeForce GTX 285 takes two power cables leaving none for the NVIDIA card.

But I noticed there's a cable left for a second dvd burner could I use that for my second card or can I split one of the two available for the grfx cards?