That is out of tolerance. You should double check it with a digital multimeter. Measure between the yellow (positive lead) and black wire (negative or ground lead) on one of the 4 pin drive power plugs.
If the PSU is still under warranty, you should replace it. If it is out of warranty, you have a decision to make.
Is this for the 12 volt behavior or -5 volt behavior. I measured using Si Sandra Lite software.