Question Corsair RM850x 2024, brief fan clicking on startup but only sometimes.

[fishyjack]

I have a month-old Corsair RM850X 2024 (The one with the manual fan speed adjuster).

It's hot where I live, my room does not have AC so I keep the fan on all at times on it's minimal setting and adjust it manually whenever I start gaming. I've noticed something whenever I forget to set the speed back to minimal when I turn off my PC -

Sometimes (not all the time), whenever I do a fresh boot, the fan will make a very brief clicking sound. Like brief as in not even a second long. It's 3 clicks in a rapid succession and then it is completely silent for the rest of the day. It's a very consistent sound. It's not the click of the power-inrush-relay-thing as that happens a few seconds later.

I'm fairly certain it's the fan because it has only occurred whenever the fan-speed knob was set to higher than minimal. Whenever I boot with the fan off or set to it's minimal setting, I don't hear the sound (as of yet).

I've already checked the PSU thoroughly - it is clean and there are no wires or cords making contact with the fan.

My GPU has passive cooling and whenever the fans kick on there is an audible click from the motor (GTX 1660 super, apparently considered 'normal' behavior). So my first thought is that since this PSU also has 'passive cooling', the click could just be from the motor turning on and instantly going to a higher RPM? The fan click from the PSU and fan click from my GPU sound identical.

I am only a little worried, mostly just wanting to confirm that it is indeed the fan making the noise. I'm okay with the noise if it seems like a 'normal' behavior. All GPUs and PSUs I put in my system are cursed with some sort of noise whether it be coil whine or something else xD.

Any insight is appreciated!

 

[Aeacus]

I keep the fan on all at times on it's minimal setting and adjust it manually whenever I start gaming.

I'm wondering why you even mess with the manual fan control for the PSU? 🤔

GTX 1660 Super is 125W GPU and any load on your 850W PSU would never get as high for PSU to need active cooling. So, you can just keep your PSU in zero RPM mode for forever. And when PSU does get hot, it will automatically start the fan to cool itself, when need be (e.g if load would go ~50% of PSU's max capacity or more).

I have GTX 1660 Ti GPU, with Seasonic PRIME TX-650 PSU. My PSU also has semi-passive fan profile and for the past 9 years or so, the load on PSU has never reached so high, that PSU fan needs to turn on.

 

[fishyjack]

I'm wondering why you even mess with the manual fan control for the PSU? 🤔

GTX 1660 Super is 125W GPU and any load on your 850W PSU would never get as high for PSU to need active cooling. So, you can just keep your PSU in zero RPM mode for forever. And when PSU does get hot, it will automatically start the fan to cool itself, when need be (e.g if load would go ~50% of PSU's max capacity or more).

I have GTX 1660 Ti GPU, with Seasonic PRIME TX-650 PSU. My PSU also has semi-passive fan profile and for the past 9 years or so, the load on PSU has never reached so high, that PSU fan needs to turn on.

When it's cool out, I usually just leave it alone and don't touch it. But as it's heating up, it's 80-85f in my room daily and only getting hotter. So I guess out of personal anxiety and not wanting ambient high heat + load to overheat my PSU. When I leave it on minimal speed and game on a hot day, the back of the PSU get pretty warm to the touch and it just makes me worry.

Do PSU's ramp up fan RPM based on temperature too? I only ever see it mentioned Loads.

 

[Aeacus]

But as it's heating up, it's 80-85f in my room daily

I live in the world of Celsius, so, it would be 26.6C to 29.4C, which is actually the same ambient temp as my room usually is. Currently, my ambient temp is 27C.

And if you look at PC components, they all report their temps in Celsius as well.

and not wanting ambient high heat

Well, you could stop gaming then. 🤔 Since gaming puts higher load on CPU and GPU, making them both waste a lot of power as excess heat and in turn, heating up your room even more.

But to keep ambient temp lower, open up the room door and window or two. Oh, floor fan also helps to circulate air to/from the room.

load to overheat my PSU

Your PSU is designed to withstand up to 50C (122F) operating temp. So, unless your ambient temp isn't 50+C, no need to worry.

When I leave it on minimal speed and game on a hot day, the back of the PSU get pretty warm to the touch and it just makes me worry.

Human body temp is ~37C. For you to feel something hotter, the temp would be ~40C or so. Now, if temp would be 44C and up, you'd feel pain when touching it.

Lloyd-Smith and Mendelssohn found the pain threshold to be 44.6°C (112.3°F). Defrin et al. investigated heat pain threshold across the body and found the lowest level in the chest (42°C or 107.6°F), the highest in the foot (44.5°C or 112.1°F) and the hand was 43.8°C (110.8°F).

Source, white paper (*.pdf download): https://ntrs.nasa.gov/api/citations/20100020960/downloads/20100020960.pdf

Back of the PSU being ~40C is still ways to go before internal temp would be an issue for the PSU. So, you'd be still good leaving the default fan profile (zero RPM mode).

Here's another viewpoint: the more you manually keep the fan spinning - the faster the fan wears out. Whereby the fan may not last the 10 year warranty period the PSU has. And once the fan dies, PSU would not work (or work until OTP kicks in and kills the power to the PC). So, keeping the fan at 0 RPM actually extends the lifespan of the fan as well.

Do PSU's ramp up fan RPM based on temperature too? I only ever see it mentioned Loads.

OTP covers it. And since your PSU has dedicated fan controller chip (namely Microchip PIC16F1503, source: Cybenetics report), the fan does react to the PSU's internal temperature as well.

On top of that, your PSU also has fan failure protection, so when the beefy 140mm fan should die, PSU won't let itself to cook up.
Your PSU protections listed in review: https://hwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-review/8/

With all that said, i see no reason why you'd need to fiddle with manual fan control.
Now, if the load on PSU would be 700-800W at all times, then yes, PSU internals would heat up and active cooling is needed. Which PSU takes care automatically.
But for a mere ~200W load (if even that), PSU won't heat up to the point where it triggers the fan and active cooling starts.

 

[fishyjack]

I live in the world of Celsius, so, it would be 26.6C to 29.4C, which is actually the same ambient temp as my room usually is. Currently, my ambient temp is 27C.

And if you look at PC components, they all report their temps in Celsius as well.


Well, you could stop gaming then. 🤔 Since gaming puts higher load on CPU and GPU, making them both waste a lot of power as excess heat and in turn, heating up your room even more.

But to keep ambient temp lower, open up the room door and window or two. Oh, floor fan also helps to circulate air to/from the room.


Your PSU is designed to withstand up to 50C (122F) operating temp. So, unless your ambient temp isn't 50+C, no need to worry.


Human body temp is ~37C. For you to feel something hotter, the temp would be ~40C or so. Now, if temp would be 44C and up, you'd feel pain when touching it.

Source, white paper (*.pdf download): https://ntrs.nasa.gov/api/citations/20100020960/downloads/20100020960.pdf

Back of the PSU being ~40C is still ways to go before internal temp would be an issue for the PSU. So, you'd be still good leaving the default fan profile (zero RPM mode).

Here's another viewpoint: the more you manually keep the fan spinning - the faster the fan wears out. Whereby the fan may not last the 10 year warranty period the PSU has. And once the fan dies, PSU would not work (or work until OTP kicks in and kills the power to the PC). So, keeping the fan at 0 RPM actually extends the lifespan of the fan as well.


OTP covers it. And since your PSU has dedicated fan controller chip (namely Microchip PIC16F1503, source: Cybenetics report), the fan does react to the PSU's internal temperature as well.

On top of that, your PSU also has fan failure protection, so when the beefy 140mm fan should die, PSU won't let itself to cook up.
Your PSU protections listed in review: https://hwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-review/8/

With all that said, i see no reason why you'd need to fiddle with manual fan control.
Now, if the load on PSU would be 700-800W at all times, then yes, PSU internals would heat up and active cooling is needed. Which PSU takes care automatically.
But for a mere ~200W load (if even that), PSU won't heat up to the point where it triggers the fan and active cooling starts.

That's .. a lot of information but thank you, haha. I do keep multiple fans going, door open and windows open with fans in them. My home (and my room especially) has poor insulation and is positioned where it gets blasted by the sun, despite thick blackout curtains and 'sun-proof screens' on my windows.

I suppose I am just overly cautious and sometimes it's difficult for me to trust things at face value. I recall seeing somewhere on the Tomshardware review for the RMX 2024 that it 'loses efficiency in hot environments' so I guess that made me more unsure. Took me a *long time* before I was okay with using passive cooling GPUs even though it's standard now. I'll leave it back to default and monitor.

Seriously, thank you for providing very thorough information. You didn't need to, but you did and that's really nice .

 

[geofelt]

Why not contact Corsair for an authoritative answer to your question?

 

[Aeacus]

I recall seeing somewhere on the Tomshardware review for the RMX 2024 that it 'loses efficiency in hot environments' so I guess that made me more unsure.

That is true. However, the review that you read, was RM750x (2024) and not RM850x (2024).
TH review: https://www.tomshardware.com/pc-com...750x-2024-psu-review#section-hot-test-results

During hot testing, the Corsair RM750x (2024) experiences a significant decrease in efficiency, mostly under heavy loads. Efficiency drops to 88.1% at 115 VAC and 90.4% at 230 VAC, compared to 89.6% and 91.9% during cold testing. This efficiency degradation of approximately 1.3% is atypical for a high-quality unit but there are no signs of thermal stress. Unfortunately for the RM750x, this degradation causes it to lose the Platinum certification.

Meaning that RM750x (2024) can not be rated 80+ Platinum, instead 80+ Gold, which it is.

Now, if you read reviews of actual PSU what you have, RM850x (2024) then you can see that 850W version fares much better efficiency wise;
HWbusters: https://hwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-review/7/
KitGuru: https://www.kitguru.net/components/...orsair-rm850x-atx-v3-1-3rd-gen-2024-review/5/
Guru3D: https://www.guru3d.com/review/corsair-rm850x-psu-review/page-7/#efficiency

Also, do note that PSU is most efficient when the load on it is 50%-80% of it's max rated capacity. If you go with 90% or 100% load, efficiency will drop for all PSUs.
E.g here's efficiency results for my Seasonic PSU,
TH review: https://www.tomshardware.com/reviews/seasonic-prime-titanium-650w-psu,4690-5.html

Now, my PSU is 80+ Titanium and most efficient PSU out there, but even the very best has efficiency drops when load surpasses 50% mark.

As i said before, load on your PSU is ~200W (if even that) and there are 0 concerns for you to stress over your PSU's efficiency.

 

[fishyjack]

Why not contact Corsair for an authoritative answer to your question?

TBH, it hadn't actually occurred to me. Long history of customer support copy-pasting generic responses whenever I was experiencing an issue, no matter the severity. Took me a bit to find the support email for corsair (the fact that it's seemingly not on their website at all is a little weird). Sent an email detailing the issue and got a response within seconds from an AI saying that 'it was most likely just the fan motor kicking on and adjusting to the set speed, but since it doesn't persist then it's 'normal'. If it changes or gets worse, send another email / support ticket.'

That is true. However, the review that you read, was RM750x (2024) and not RM850x (2024).
TH review: https://www.tomshardware.com/pc-com...750x-2024-psu-review#section-hot-test-results


Meaning that RM750x (2024) can not be rated 80+ Platinum, instead 80+ Gold, which it is.

Now, if you read reviews of actual PSU what you have, RM850x (2024) then you can see that 850W version fares much better efficiency wise;
HWbusters: https://hwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-review/7/
KitGuru: https://www.kitguru.net/components/...orsair-rm850x-atx-v3-1-3rd-gen-2024-review/5/
Guru3D: https://www.guru3d.com/review/corsair-rm850x-psu-review/page-7/#efficiency

Also, do note that PSU is most efficient when the load on it is 50%-80% of it's max rated capacity. If you go with 90% or 100% load, efficiency will drop for all PSUs.
E.g here's efficiency results for my Seasonic PSU,
TH review: https://www.tomshardware.com/reviews/seasonic-prime-titanium-650w-psu,4690-5.html

Now, my PSU is 80+ Titanium and most efficient PSU out there, but even the very best has efficiency drops when load surpasses 50% mark.

As i said before, load on your PSU is ~200W (if even that) and there are 0 concerns for you to stress over your PSU's efficiency.

Yeah, I kinda know my way around PC's but PSUs are always the thing that confuses me the most. Thank you. For now, I will keep the fan off / default and just make sure there's enough airflow in my room and around my desk.

 

[Aeacus]

the fact that it's seemingly not on their website at all is a little weird

In today's day and age, the "AI chatbox" (Web Widget) is the current norm for customer support. Only when AI can't answer your inquiry, you get to open actual support ticket where actual person views your submission.

Guide on how to do it: https://help.corsair.com/hc/en-us/a...o-I-get-a-replacement-for-a-defective-product

Sure, that guide is under RMA section but it shows how to bypass the AI chatbox to open up the support ticket.
(Took me some time to find that guide. Some years ago, pre-COVID, Corsair had better support system, where you logged in to the support site and opened the ticket freely. Now, you have to go through AI to open the ticket.)

 

[fishyjack]

In today's day and age, the "AI chatbox" (Web Widget) is the current norm for customer support. Only when AI can't answer your inquiry, you get to open actual support ticket where actual person views your submission.

Guide on how to do it: https://help.corsair.com/hc/en-us/a...o-I-get-a-replacement-for-a-defective-product

Sure, that guide is under RMA section but it shows how to bypass the AI chatbox to open up the support ticket.
(Took me some time to find that guide. Some years ago, pre-COVID, Corsair had better support system, where you logged in to the support site and opened the ticket freely. Now, you have to go through AI to open the ticket.)

Thanks, yeah. Bookmarking for future reference.

Also, realized it's not the PSU fan making the noise. Sound just travels oddly in my tower but I heard the noise twice over four days with the PSU fan off. Monitoring every time I turn on my PC, pretty sure it might be one of the stock case fans on my tower. Both are quite old, 3-4 years iirc.

 

[Aeacus]

Also, realized it's not the PSU fan making the noise. Sound just travels oddly in my tower but I heard the noise twice over four days with the PSU fan off. Monitoring every time I turn on my PC, pretty sure it might be one of the stock case fans on my tower. Both are quite old, 3-4 years iirc.

Open the side panel of your PC and put your ear to it, to locate from where the sound comes from.

Not that many moving parts inside the PC. My best bet would be HDD reading arm/head reset, IF you have HDD in the system. If no HDDs, then fans would be 2nd one to look at. AIO pump as well, IF your CPU has AIO cooler on it.