We take our noise measurements with the sound meter positioned 1 foot from the graphics card. I measured the sound floor to be 34 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 20 times. An idle reading comes after leaving the system on the Windows desktop for 30 minutes.
While it is not quite as loud as the reference air-cooled RX Vega cards, the ASRock RX 580 is certainly a fairly noisy aftermarket card. It does have a ‘fan stop’ mode so the two 85mm fans stop spinning under light loads, but under load the fan speed reaches around 2500rpm and that causes the relatively high levels of noise.