Hi, looking at my scenario, MacPro 4.1 system with firmware updated to 5,1 and upgraded 2xCPU X5690 3.41Ghz , 12 GB RAM, 240 GB SSD/MSATA Kingston PCI, USB 3.0 PCI, and only two hard disk days connected. Now with a GT-120 GPU just to consider overall power. So for now only have 2 x sata connectors, from the free hard disks bays, available to power the GTX 980 TI. My main idea, is to buy the most simple & powerless GTX 980 TI reference card from ZOTAC or EVGA and PC model, since where I live (Brazil) its quite impossible due the costs+taxes(60%!) to buy from www.macvidcards.com ... unfortunately!! Even don't want to buy the overclocked models, and also not considering to overclock the reference card itself, specially to avoid more power needed and risks associated with Mac Pro power supply limitations and without using any external supply. My question is related with the most missing part about the GTX 980 TI with MacPro 4.1/5.1 and not using external power supply. What is the best way to plug the 6 and 8 PIN cables? There are many posts everywhere, affirming that there is no need to have a external power supply or by the other side from other posts advising for sure you need a external power supply if you don't want to damage the motherboard. So the GTX 980 TI reference card is compatible or not without any external power supply? Considering if 6 PIN expect 75 Watts and 8 PIN expect 150 Watts in the GPU plugs. And since MacPro has 2 x 6 PIN in motherboard, each can drive 75 Watts, so this could be enough to power to 8 PIN in GPU? If only remaining 2 x Sata plugs available, will this be enough to feed the power in the 6 PIN plug in GPU? Or should be considered to used all 4 x Sata to feed one single 6 PIN plug in GPU to minimize risks from the motherboard being damaged? How MacVidCard guys recommend the GTX 980 TI connection without external power supply? Any other risks related with if not using MacVideo firmware custom cards modifications? Thanks!