Hello all. I'm new to the whole Mac world. I just bought a 2010 Mac pro 5,1 running Mojave. Still has the non metal supporting 5870 in it so it is very hard to use. I bought asi Radeon r7970 and discovered it has a 6 pin and 8 pin connector. Spec sheet say it draws 275w max load. So the only way (short of pixels mod or external PSU) I can power it safely is dual mini 6pin from main board to the 8 pin on 7970 and then a dual data to 6 pin on 7970. That should give me 333watts. Is this correct or does it not work like that? Thanks for the help this forum has be extremely helpful.