Whoever is going to build these will sell a lot!
Since many PSU dedicate a full 18-20amp rail for CPU (220w) while they usually consume 20-60w, we need 4pin CPU to dual 6pin PCI-e adapter to use CPU amps for GPU
You can mod you PSU yourself it would usually void your warranty, unless you use a special tool to pull-out the connectors.
I modded about a dozens of PSU to pull juice from the 8pin connector,
I'm really tired of it, I use the special tool and even then it's a pain.
Please someone make this cable and sell them for BTC !