I have noticed the same thing with my strix.. Is the white LED shining bad?
EDIT: found this:
"The card is powered by one 6-pin PCI-E and one 8-pin PCI-E connection, a slight upgrade over the dual 6-pin reference design and over the Strix GTX 970 which uses only an 8-pin one. More available power doesn't always equate to better overclocking, but it certainly helps. LEDs on the rear of the PCB turn from red to white to let you know that you've properly connected these power cables."
