Hi,   The GPU install kit, are you referring to this: [URL] the GPU enablement kit. The power cable should connect to the riser power connector, located at the end of the riser. Try install 1 GPU at a time.   What PSU watt are you using? The PSU settings must be set to non-redundant. 
Hello, I try to install three GPU Nvidia Tesla M60 in a Dell R740. I use GPU install kit, that come with a cable that have one connector with 6 pins, and the other connector have 6 pins + 2 pins. The Tesla M60 have a power connector with 8 pins. So...I connect 6+2 pins in Tesla GPU Power connector, and the other connector side in the mother board power supply. When i have the three GPU connected, the server don't power up. The PSUs are alerted (orange blinked). When disconnected the GPUs, the server power up.  The questions is: Its necesary and extra power cable to connect the GPUs to the power? I find in the Tesla manual, that is not compatible connect directly an PCIe cable power to GPU. Tesla M60 Cable Attachment Support Notes: CPU-8-pin auxiliary power cable attached: Supported; required. CPU 8-pin cable must be attached. CPU 8-pin cable must carry up to 240 W. PCIe 8-pin cable: Not supported. PCIe 8-pin cable is not compatible with CPU 8-pin board connector. Plugging in forcibly can cause permanent damage to the board and the system. In Dell manuals and docs, i not find any issue with cable power that come in install kit. Any sugestions? Thanks in advanced!
Dell R740 & Nvidia Tesla M60