Will this connector give me problems for a HD7790?

[Manatubear]

I have a 500w Tacens PSU (generic) that only has 1 power sata 15pin connector and one 4 pin molex free.
I want to connect a HD7790 to the pc, and it comes with a molex to pcie 6 pin cable, however my molex connector has an adapter taking some power to the CPU fan.
( http://i.imgur.com/mk28hn2.jpg )
Since the 7790 uses a max of 80-100w, would it be ok to use that molex connector (since it can also get some power from the PCIe), or should i get a Sata 15 pin to pcie 6 pin cable instead?

Also, if im using Catalyst 13.12 already, do i need to uninstall it and reinstall it for the new GPU?
(my current GPU is a lower end Radeon, but this one doesnt require extra power)

 

[markwp]

You'll be fine using the molex. No need to change drivers unless you want to update.

 

[Manatubear]

You'll be fine using the molex. No need to change drivers unless you want to update.

Thanks!!!

 

[markwp]

Welcome