RX 580 is no louder than any equivalent performance card but it's honestly it depends on the specific card model, not just "RX 580". One model of RX 580 might be somewhat loud while another with a better cooling configuration might be nearly silent most of the time and then barely audible under a load. It also depends a lot on what the rest of your cooling system consists of. If you have an air CPU cooler and a few case fans, you may not notice it above the noise they make at all.