Question About the Humming Sound from the PSU – It Doesn't Resemble Coil Whine [Extended]
Question About the Humming Sound from the PSU – It Doesn't Resemble Coil Whine [Extended]
Usually when I ask others about my PSU, they mention buzzing, which I later understood was the GPU's coil whine. However, recently I noticed a noticeable, somewhat loud humming coming from the PSU area. The sound resembles a steady "mrrr," similar to airflow noise, but it feels unusual to me. It could have been there all along, yet I became aware of it because it interferes with the background noises I usually hear at the back of the PC.
The hum isn’t constant; it disappears when there’s less load or after a game ends. When it does occur, it’s mostly a continuous "mrrrr" with minor volume changes, like gentle waves, but it sounds static to me. It seems distinct from the fan’s rotation and becomes noticeable when the fan is under stress.
At startup, the fan operates clearly, but no humming is present, suggesting the sound likely comes from elsewhere. I suspect this pattern emerges after running certain benchmarking games or playing titles like Nioh 2 and Elden Ring.
- When the fan spins faster, the hum fades or becomes much quieter; I thought it might be masked by the fan noise, but it wasn’t loud enough to completely cover it. On a few occasions, the hum just stopped abruptly when the fan increased speed.
- Closing applications causes the hum to rise again, almost as if it’s linked to changes in fan speed.
I’ve recorded a couple of videos to document the noise, though they don’t seem very effective. I believe the hum mixes with the airflow over the microphone and is hard to detect clearly—especially without headphones or when the ceiling fan isn’t running. My main concern is whether this noise indicates a problem or is just background interference.
I consulted techpowerup forums, but the advice didn’t help much. I narrowed it down to the PSU, noting it’s most noticeable near the bottom of the case or close to the PSU vent. Someone suggested it could be a transformer humming, though I’m still unsure, especially considering how the noise reacts to fan speed changes.
The PSU doesn’t feel unusually warm, and CPU/GPU temperatures are normal, along with power consumption. The fan’s sound remains consistent—just louder under load. In games like Roblox, the opposite happens: the hum is more prominent and doesn’t reduce when the fan slows down. It also continues after the game ends, just like other applications, fading out when idle again.
Here are the links to the videos I made:
https://imgur.com/a/iqsUhrl
https://imgur.com/a/Unf09Tp#bhrqUf4
These should provide some insight, though they might not be very helpful. It’s best to set the volume at 100% if you decide to listen. Either way, I’ll keep recording. The PSU is a Phanteks Revolt 1000W, paired with an Asus B550-F motherboard and an RTX 3070 GPU.
Dust accumulation on the PSU fan blades may lead to the observed noise, and a loose dust particle falling off could create a distinct mark.
odd, there shouldn't be that much dust in the PSU; it has a mesh panel at the bottom to assist, though it doesn't fully prevent accumulation. I'm also aware the panel was cleaned only a few weeks ago. I've had this PSU for about six months, and my older power supply was in the same place for years without any noticeable dust buildup, even though the old PC was there. edit: it would make sense but I'm not sure if it's accurate; on startup and during some games, the humming just disappears completely or isn't present at all. The fan also doesn't produce any sounds indicating dust presence, and it's not spinning faster than before.