Dear Greybeard thank you for your reply. The PCIe cables that come with the HX1200i are daisy chained (pig tailed), meaning the 8 pin and 6 pin are on the same cable.
Since I have 3x R9 290's I have to use a single cable (with 8 pin and 6 pin on one cable) for each of them (so 3 cables)... However can the 8 pin and 6 pin on one cable deliver 225W of power (+75W from the slot itself) to the card...
So I am wondering that the daisy chained cable can actually provide 225W of power.... Can it?