Running Dual GTX 1080 Ti with PSU Extended Card 10pin slot
I would like to connect a second GPU (an Nvidia GTX 1080 Ti) to my Dell Precision 5820 with a 950W PSU.
The problem is that each GPU needs a 8pin and a 6pin power connector, but there are only two 6+2pin PCIe cables in the machine. Both of them are connected to the slots of the Power Supply Extended Card that are tagged with "VGA".
However, the Power Supply Extended Card also has a free 10pin socket of the same type as is used to connect the CPU, so I wonder if it could be used for this purpose.
This unanswered post mentions a a cable that has a male 10pin to 6+2pin and could therefore possibly fit for this (I could split it with a 8pin to 2x6pin). I found this cable on ebay which looks just right. But since there is hardly any documentation on this 10pin socket I wonder if this will actually work.
This post mentions that powering a GPU from a certain power module failed, but it is unclear whether it is the same socket. A similar question has previously been asked here and here, so there is a lot of interest in getting this to work.
So the question is: Can the free 10pin socket be used to power the two 6pin slots of the GPUs?