also it was measured at the wall so it really used ~90% of that.
but if you read the graphics card review, the cards slightly throttled due to heat from being close. so if you remove the throttling that would be pretty close to spot on.
Adding a second card increases power consumption by less than 200W. We feel as if the power consumption would be closer to 500W if both Palit cards were running at the same core frequency and voltage as the single card.