Ako 6-pin ima samo 2x12V onda je moguće samo 75W al pošto većina novih i kvalitetnijih PSU ima na 6-pin 3x12V onda itekako ide preko 150W.
Even in the worst case scenario, the PCI-E 6-pin connector can handle 177 - 207W of power draw. The worst case scenario being: 2/3 VDD and VSS pins connected on the PCI-E power connector and low grade connectors used in the power cable or in the cable header. Low grade connectors are rated for 8A per contact and the high grade ones are rated for 11A. The ATX specification recommends to use 16AWG wires (12A rated each) for these connectors but allows 18AWG (8.6A rated each) to be used. So at minimum you are looking at 16A at 11.04V - 12.96V.
And when a fully connected high quality connector, paired with 16AWG wires is used you can draw safely at least 265 - 311W from a single 6-pin PCI-E connector. If your PSU can deliver, that is.