Question about GPU for Mac Pro 3.1

I have a Mac Pro 3.1 and also have a ASUS GTX 780. I found online that it is supported in later macOS without a boot screen. Now the problem is: the GPU has 1 6pin power connector and 1 8pin. Can I use a cable like the one I’ve linked to? I won’t be using a lot of processing power. Only like to play around a bit with Xcode.