We take our noise measurements with the sound meter positioned 1 foot from the graphics card. I measured the noise floor to be 32 dBA, thus anything above this level can be attributed to the graphics cards. The power supply is passive for the entire power output range we tested all graphics cards in, while all CPU and system fans were disabled.
A reading under load comes from running the 3DMark Fire Strike Ultra stress test for 30 minutes. An idle reading comes after leaving the system on the Windows desktop for 30 minutes.
As for noise levels, we'll start with the P BIOS. In this mode, the fans spun at around 1530rpm, or 46%. Even using that performance BIOS, noise levels did not exceed 40db which is a fantastic result.
Things are even better using the Q BIOS. Fan speed slows to just over 1000rpm – or 32% – and at that speed, the card is practically silent. I had to move my ear right next to the card, on our open test bench, before I could hear the fans whirring away very gently. If you had the card in a case, using the Q BIOS, you simply would not be able to hear it. It's a fantastic piece of work from ASUS ROG.