Corsair AX 1000 PSU Fan randomly spins up like on self-test if powering-on the PC

[HubiHh]

Hello, everyone, I have had the Corsair AX 1000 power supply for about 9 months. I recently noticed that the fan turns up briefly at medium and nearly high loads (CPU Max 200 watts and graphics card 300 Max). This is the same sound as when switched on, where it revs up briefly and then continues to run "normally" again. This phenomenon is in zero fan mode and also in operation in which the fan rotates continuously in silent mode. I only recently noticed this behavior. Is this normal, or is maybe the fan control faulty? I took an extra 1000 watt power supply to have peace of mind. Components are a MSI RTX 2080 TI Gaming X Trio with a minimally overclocked I10900 KF in a Thermaltake View 51 with a total of 12 fans. Of course it can be that so many fans trigger the rail. But why does it turn up briefly? Airflow is barely enough. Of course, the fan of the power supply also points outwards in the direction of the dust filter. The power supply  isn't exactly the best value for money in terms of price ratio. So it would be sad if the noise stayed continously in the future. Or really a normal behavior? It's also based on the Seasonic Prime series. Possibly Corsairs fan curve is maybe  too aggressive? Unfortunately, you can only regulate the I-Series models in ICue. 

Best regards 

[c-attack]

It is normal. I have the sister Seasonic model. To turn on the fan it applies a typical 12v “start up voltage”, which is the whir you hear before standard 5-12v fan control kicks in. This is how the majority of PSU models operate their fan control and turn on. The fan start up point is a combination temperature/wattage trigger and can be activated by either reaching a specific point. Should be around 400W on that 1000W model. 

Edited April 15, 2022 by c-attack

[HubiHh]

Thank, ou very much for the detailed explanaition 👍😃

[HubiHh]

Thank, ou very much for the detailed explanaition 👍😃

 

Do you reommend the zero Fan Mode? Iam still using now silent Mode as wellnas for the gpu. I am more an Fan of continously running Fans instead of start stop. Bit thats antther topic. Dies ist matter for a psu? Best regards 

Edited April 16, 2022 by HubiHh

[c-attack]

I went through the same analysis and one point. People will argue the constant running fan brings more dust into the PSU, but there are relatively easy solutions for that. If you think you will continue to use it for the next 10 years, then maybe fan bearing longevity bears consideration.
 

However, for most people this is going to be about noise. My Seasonic version is too loud for my liking with Eco mode off and the fan in the lowest state when I’m quietly working. Its sound rises above the other 9 fans in the case. So while I don’t like the 12v power on I hear through my headphones when gaming, that is a momentary distraction vs the constant irritation at idle.
 

Where it can be problematic is when you are straddling the temperature or wattage trigger for the fan. On one of my older systems with less combined cpu+gpu power I was constantly hopping across on the on/off state and it might trigger 4-5 times per hour. That was too much and I made a change on the PSU to a 1200 AXi that had user fan control, an undetectable baseline 750 rpm fan, and a slightly higher wattage trigger. Unfortunately user controllable PSU fans are very rare at the moment and PSUs still pricier than normal. You’ll have to assess how often this occurs in one sitting vs the baseline noise with it on. 

Edited April 16, 2022 by c-attack

[HubiHh]

My psu is nearly so quiet that the other twelve Fans are much noisier. In terms of long term a running Fan shoud be better? The idle background noise is nearly not noticable. Thank you for your reply. 

Edited April 16, 2022 by HubiHh

[c-attack]

If noise is not a factor, then it’s mostly about fan longevity. If you run your PC 24/7, I would probably not turn off eco mode to make the fan constantly run. If you use it for more distinct time periods, you can run the fan and not come close to the Mean Time Before Failure. As for any performance benefit, it’s likely none unless you have sone unusual environmental circumstances or if the fan is triggering on/off at the idle desktop state. 

Edited April 16, 2022 by c-attack