To test the power consumption of the Sapphire Vapor-X R9 290, the test system was plugged into a Kill-A-Watt power meter. For the idle conditions, the system was allowed to sit at the desktop for 30 minutes with no software running. For the load conditions, Crysis 3 was played for 30 minutes in Eyefinity mode (5760×1080) and the peak power reading was recorded.
After the testing was finished, I decided to try the GPU on a slightly less powerful power supply; seeing as the entire system maxed out at 429W when it was overclocked. A Lepa 650W power supply was installed, and a few benchmarks were re-done. No noticeable impact to the performance when running below the required amount. This goes to show that manufacturers are still inflating their requirements, having a quality power supply is still very important.
Power Consumption Results: The system idled at 109 Watts, without overclocking, the system pulled 356 Watts at the wall during a 60 minute gaming session of Crysis 3. Sapphire states that a 750W power supply is recommended for the video card, which is overkill in my opinion; not a bad idea though.