For testing power consumption, we took our test system and plugged it into a Kill-A-Watt power meter. For idle numbers, we allowed the system to idle on the desktop for 15 minutes and took the reading. For load numbers we ran three games at 1920×1080 and averaged the peak results seen on the power meter.
Power Consumption Results: Power numbers look pretty solid across all three AMD Radeon R9 280X video cards. The entire platform ranged between 105-108 Watts at idle and 366-383 Watts at load. The ASUS Radeon R9 280X Top Edition card used the most power at 383 Watts, which is 15-17 Watts more than the cards by XFX and MSI. The ASUS card has more power phases, which is likely why is uses more power.