What's more interesting than performance is the energy consumption, and we did three tests in this area. The chart at the top shows the idle usage on the Windows desktop, the average over a five-minute period. The second chart shows the average usage during a complete run of 3DMark Vantage on the integrated GPU. The third chart shows the maximum energy consumption during Cinebench 11.5.
There are some more signficant differences here, particularly for idle usage. The least efficient board uses twice as much as the most energy-efficient one.
The ASUS P8Z77-V LX uses a little more power than average, and that's actually a little disappointing for a motherboard that doesn't have a lot of power-hungry features.