2 gpus, 1 psu

[240_17user]

K. I have asus R9 280x and psu corsair hx 650. That boi has blue 2x8 pci-E and black 6x6 Periferals and Sata connections. My other GPU only needs 8pin pci-E, however, R9 280x boots only when it starts on all 2 blue 8 pci-E (16) but it should take only 6+8 (1x6pins from Periferals and Sata, and 1x8pins pci-E), where in last case system won't boot at all, only half sec coolers lights and done, no response until O/I PSU .
I want to give 1x8pin for each of my gpus , and add 1x6pin for R9 280x and boot all of that somehow.
I know that I could solder 8+6 just into 8pin and it should work but I never done this before, or probably my system won't boot because 6pins power really only for Periferals and Sata, or it start work not at the same moment with 8pins, don't know.
Help pls to find best cheap and fast solution for me.

 

[Zerk2012]

What is your other video card if your running 2X 280X then that has a TDP of 500 watts so your PSU is not big enough.
A general rule of thumb if your PSU don't have the proper connectors then it's not good enough.

 

[240_17user]

The problem is not the power supply size, because it couldn't run solo in 6+8 mode, only in 8+8, but card has 14 pins

 

[240_17user]

What is your other video card if your running 2X 280X then that has a TDP of 500 watts so your PSU is not big enough.
A general rule of thumb if your PSU don't have the proper connectors then it's not good enough.

I never said about 2x 280x, read carefully, ty.