Area-51 R2, motherboard, PCIE_PWR1 connection

x3 red PSU 6pin ends plug into R7 R8 R9 (CPU/MB)(above)

short black 8pin is (augmented) GPU power (PCIE_PWR1)

long black 8pin is CPU power

both black 8pins plug into motherboard

GPU (PCIE_PWR1)(short) into bottom of board, CPU (long) into top

PCIE_PWR1 is augmented (more + direct) 12volts to your GRFX card(s) PCI-E gold contacts in the PCIE slot

Plug yours into bottom 8pin header seen below

Below, Right, CPU = 30 GPU = 18

Should probably change the title from:

alienware area R1 motherboard connection problem

to

Alienware Area-51 R2 motherboard PCIE_PWR1 connection

... will help others searching later.