To get a sense of how much each of the cards we tested contributed to system power draw, we stood still in a visually-complex area of Hitman's Paris mission and checked readings on our trusty Watts Up power meter. Our monitor and any other test hardware were connected to the wall using a separate power strip.
Well, that's something. Nvidia's Pascal cards continue to be the efficiency champs, and it appears AMD's increased board power for the RX 570 and RX 580 is a factor in reaching higher clocks. The RX 570 doesn't need much more power to hit its boosted clock speeds versus the RX 470, but Sapphire's RX 580 needs even more than its official 30W board-power bump to hit its impressive boost clocks.
To get a sense of how noisy each graphics card on our bench today gets under load, we used the iPhone app SoundMeter by Faber Acoustical. Each measurement was taken 18" from the fans of the graphics card while it was running our Hitman load.
Our XFX Radeon RX 470 and RX 480 aside, most of the cards here are quite tolerable given our test environment's 29.8 dBA noise floor. Despite its hefty power draw, Sapphire's Radeon RX 580 remains quite pleasant and neutral-sounding under load, save a tiny bit of coil whine. Even if your power bill is suffering with this card in your system, your ears can rest easy.
MSI's RX 570 is also quite nice-sounding despite its relatively high reading on our iPhone dB meter. The company's Twin Frozr VI cooler might be a bit too effective in some circumstances, though. I noticed the fans on this card would sometimes stop and restart during our tests, as if the cutoff point for the card's semi-passive mode was set too high. This on-off-on cycle could prove more annoying to some builders than a constant gentle noise, and I hope MSI can fix it in a future driver or firmware update.