We measure system-wide power draw from the wall while the card is sat idling at the Windows 10 desktop for 30 minutes. A reading under load comes from running the 3DMark Fire Strike Ultra stress test 20 times.
With the OC BIOS, power draw is about 30W higher than the reference card – making this the most power-hungry custom Navi card yet. The Silent BIOS does reduce this by around 40W, meaning it actually draws less power than the reference card due to its lower clock speed.