Four Titan X superclocked crashes with latest driver

When I run nvidia-smi, it crashes the machine and gives a bunch of trace information. Then it hangs and I have to reboot the machine.

Motherboard: ASRock x99 ws/e 10G
GPUs: 4 Titan X superclocked
NVIDIA driver: 367.27. I tried a couple different ones.
Cuda version: 7.5.18

Somehow I could run with 2 GPUs without a problem.
With 3 GPUs the nvidia-smi runs ok, but my multi-gpu program will crash after a while and the machine rebooted itself.
With 4 GPUs nvidia-smi will crash the machine.

Also in the bios setting if the all the PCIe set to “Gen1” it works. But if I change it to “Auto” it will fail.

Any ideas?

The os is Ubuntu 14.04 LTS. The kernel version is 3.13

What kind off power supply do you have?

EVGA supernova 1600 G2