To test power consumption today we are using a Keithley Integra unit and we measure power consumption from the VGA card inputs, not the system wide drain. We measure results while gaming in Tomb Raider at 4k resolution and the synthetic stress test Furmark – recording both results.
The Sapphire R9 285 ITX Compact is the more power hungry graphics card, taking around 200 watts when gaming. This rises to 250 watts under synthetic Furmark load. The MSI GTX760 Gaming Mini ITX by comparison only takes 160 watts when gaming.
Obviously when we compare these Mini ITX solutions to the latest Nvidia Maxwell architecture we can see massive differences. The reference Nvidia GTX980 demands 2 watts less than the GTX760 we tested today when gaming. Incredible really.