Corsair RMx - changing the fan

[Stahlmann]

Is it possible to change out the included fan on the corsair RMx 850W? I know it will probably void the warranty and i'll probably not do it because i know nothing about how a PSU works. Are there any risks involved when it's not plugged into the wall?

[Moonzy]

8 minutes ago, Stahlmann said:

Are there any risks involved when it's not plugged into the wall?

capacitors can hold charges even when not plugged in

 

they're like batteries, if you will

 

edit: it's also a 2 pin DC fan with no monitoring(?)

Spoiler

https://www.kitguru.net/components/power-supplies/aris-bitziopoulos/corsair-rm850x-2018-psu-review/all/1/

https://www.kitguru.net/wp-content/uploads/2018/09/fan-2.jpg

so u may need to splice the new fan with the original connector, mounting wise it looks the same as standard case fans

[Elisis]

32 minutes ago, Stahlmann said:

Is it possible to change out the included fan on the corsair RMx 850W?

With what fan? Without an appropriate one for this use you'll end up worsening the PSU. And besides, why do you even want to do so?

[Stahlmann]

15 minutes ago, Elisis said:

With what fan? Without an appropriate one for this use you'll end up worsening the PSU. And besides, why do you even want to do so?

Because even with low RPMs the PSU fan is the loudest part of my system. I'd want to use a Noctua NF-A12x25, which will be better than any fan that was ever put in a PSU to begin with. But like i said, i'll probably not do it. A little noise will likely not convince me to open up the PSU and void my 10 year warranty. Just wanted to know about the risks and if standard fans would even fit.

[HanZie82]

25 minutes ago, Stahlmann said:

Because even with low RPMs the PSU fan is the loudest part of my system. I'd want to use a Noctua NF-A12x25, which will be better than any fan that was ever put in a PSU to begin with. But like i said, i'll probably not do it. A little noise will likely not convince me to open up the PSU and void my 10 year warranty. Just wanted to know about the risks and if standard fans would even fit.

You might be better of selling your current PSU 2nd hand. Then buy a new one with a no-fan mode. So when use is low the fan stops. No spinning fan no sound.

 

edit:

Wait i have the EXACT same PSU (Well almost its the 750W model). And it makes sound? Da funk? You might want to look into cleaning it (blowing the dust out) or something as i dont hear mine even when the fan is on...

[Mateyyy]

Just now, HanZie82 said:

You might be better of selling your current PSU 2nd hand. Then buy a new one with a no-fan mode. So when use is low the fan stops. No spinning fan no sound.

OP's got a Corsair RMx, which does have that functionality, beside being one of the best PSUs on the market in the noise department.

On that note, curiously, I can stick my ear next to my RM650x while running Prime95 and Superposition and not hear a thing out of it, so... pretty odd I guess.

[HanZie82]

1 minute ago, Mateyyy said:

OP's got a Corsair RMx, which does have that functionality, beside being one of the best PSUs on the market in the noise department.

On that note, curiously, I can stick my ear next to my RM650x while running Prime95 and Superposition and not hear a thing out of it, so... pretty odd I guess.

Yeah i found that out, and thusly edited my message.

 

[electropical]

11 minutes ago, Stahlmann said:

Because even with low RPMs the PSU fan is the loudest part of my system.

Most likely not the PSU, probably your HDDs causing vibration noise that you're mistaking for fan noise. I have made the same mistake not that long ago (mine is an RM750x)

Once I unplugged the HDD, I got rid of the noise.

 

19 minutes ago, Stahlmann said:

I'd want to use a Noctua NF-A12x25, which will be better than any fan that was ever put in a PSU to begin with.

This Noctua fan is good for airflow, not static pressure. Would be a terrible idea to replace the fan that comes with the RMx with any Noctua fan. 

 

[seon123]

43 minutes ago, Stahlmann said:

Because even with low RPMs the PSU fan is the loudest part of my system. I'd want to use a Noctua NF-A12x25, which will be better than any fan that was ever put in a PSU to begin with. But like i said, i'll probably not do it. A little noise will likely not convince me to open up the PSU and void my 10 year warranty. Just wanted to know about the risks and if standard fans would even fit.

Ah, yes, it must be such a big brain move to replace the PSU's 135mm fan with a smaller 120mm  fan that has even lower static pressure than the NF-F12, which already has inadequate static pressure.

Spoiler

 

[artuc]

1 hour ago, Stahlmann said:

which will be better than any fan that was ever put in a PSU to begin with

 

I counter with a summoning spell. 

 

@jonnyGURU 

[Stahlmann]

4 hours ago, HanZie82 said:

And it makes sound? Da funk? You might want to look into cleaning it (blowing the dust out) or something as i dont hear mine even when the fan is on...

4 hours ago, Mateyyy said:

OP's got a Corsair RMx, which does have that functionality, beside being one of the best PSUs on the market in the noise department.

On that note, curiously, I can stick my ear next to my RM650x while running Prime95 and Superposition and not hear a thing out of it, so... pretty odd I guess.

My PSU is 1 month old. There is no dust involved.

 

I have very high standards when it comes to low-noise. I have a pretty low noise floor in my room and i'm using open-backed headphones. I only hear some fan occaisonally spin up. As the PSU is the ONLY fan in my system that is not fully controlled according to my water temp, it's not possible that any other fan makes this "noise". To be clear it's not loud or badly distracting. And i will probably not open it up. It was just thought in my head and i wanted to know if there are risks to doing it. Now knowing that there are risks, the idea of opening up my PSU is pretty much dead.

 

Also @Mateyyy, to be fair when i had similar hardware as you my RMx 650 was also completely silent and the fan never spun in the few years i had it. But as the 3080 is a crazy powerhouse, even the RMx 850 needs to to some work to keep cool. Also both my CPU and GPU are overclocked as far as they go while being stable.

 

4 hours ago, electropical said:

Most likely not the PSU, probably your HDDs causing vibration noise that you're mistaking for fan noise. I have made the same mistake not that long ago (mine is an RM750x)

Once I unplugged the HDD, I got rid of the noise.

I don't have any HDDs in my system literally the ONLY moving parts in my system are 6 radiator fans, 1 PSU fan and 1 water pump. As everything is completely controlled to a very slow rising temperature (water), the only thing that can "spike" in noise is the PSU fan.

 

4 hours ago, electropical said:

This Noctua fan is good for airflow, not static pressure. Would be a terrible idea to replace the fan that comes with the RMx with any Noctua fan. 

4 hours ago, seon123 said:

Ah, yes, it must be such a big brain move to replace the PSU's 135mm fan with a smaller 120mm  fan that has even lower static pressure than the NF-F12, which already has inadequate static pressure.

My guess is, that you guys never tried this fan. It's literally the best allrounder fan out there when it comes to noise to performance. It is specifically meant for radiator use and has good static pressure AND airflow.

 

 

I really didn't think that this question would bring so much controversy. I was just interested if it would even be possible. Even when there would be no risks i would probably not have done it due to my PSU being brand new and still having 10 years of warranty. Again, the fan is not loud so to say. But it IS the loudes part of my otherwise completely inaudible system. I don't mean inaudible as in "noise that is not intrusive". I mean inaudible as in "i cannot tell that the system is powered on just by listening". The idea of opening up the PSU is already dead to me either way.

 

[Mateyyy]

5 minutes ago, Stahlmann said:

Also @Mateyyy, to be fair when i had similar hardware as you my RMx 650 was also completely silent and the fan never spun in the few years i had it. But as the 3080 is a crazy powerhouse, even the RMx 850 needs to to some work to keep cool.

You had a 3700X prior to the 5600X, right?

Under 100% load on both the CPU and GPU I shouldn't be too far behind a 3700X/5600X and 3080, considering how little power those CPUs draw in comparison.

 

7 minutes ago, Stahlmann said:

My guess is, that you guys never tried this fan. It's literally the best allrounder fan out there when it comes to noise to performance. It is specifically meant for radiator use and has good static pressure AND airflow.

Case fans and PSU fans are not the same thing. Yes, the NF-A12x25 is pretty much the gold standard as far as case fans go, as well as even use cases that require a fair amount of static pressure, like when they're placed right up against a heatsink or radiator.

 

With a PSU, you will require a bit more than just a fair amount of static pressure. Think about it - it's got to draw air from the tight space underneath the case (in a standard modern mid-tower), push all that air into a very tightly packed, closed off enclosure, while cooling components that can run well in excess of 100C. Even a drop in static pressure which might seem small to you, could make the difference between all the components inside your PSU being cooled well enough, and triggering OTP.

[Stahlmann]

23 minutes ago, Mateyyy said:

You had a 3700X prior to the 5600X, right?

Under 100% load on both the CPU and GPU I shouldn't be too far behind a 3700X/5600X and 3080, considering how little power those CPUs draw in comparison.

I meant my 3700X (non OC) + 1080Ti combo compared to my current 5600X + 3080 both OC.

 

23 minutes ago, Mateyyy said:

Case fans and PSU fans are not the same thing. Yes, the NF-A12x25 is pretty much the gold standard as far as case fans go, as well as even use cases that require a fair amount of static pressure, like when they're placed right up against a heatsink or radiator.

 

With a PSU, you will require a bit more than just a fair amount of static pressure. Think about it - it's got to draw air from the tight space underneath the case (in a standard modern mid-tower), push all that air into a very tightly packed, closed off enclosure, while cooling components that can run well in excess of 100C. Even a drop in static pressure which might seem small to you, could make the difference between all the components inside your PSU being cooled well enough, and triggering OTP.

Makes sense i guess. I always thought especially corsair just put something like their ML fans into the PSUs.

[Guest]

8 hours ago, Stahlmann said:

Because even with low RPMs the PSU fan is the loudest part of my system. I'd want to use a Noctua NF-A12x25, which will be better than any fan that was ever put in a PSU to begin with. 

That is a terrible idea and ill conceived.  That's not a good fan for any PSU.

 

Let's look at these four examples:

 

All four of these fans are have the same hub diameter, same outer diameter, same fan frame and exact same motor.  Yet look at how different the fan blade design impacts their airflow (CFM), static pressure (mmH2O) and noise.  Remarkable, right?

That 29.7 dB(A) on fan #4 looks mighty tempting, and 64.7 CFM is a lot of air!  Would make a great intake or exhaust fan for a case, But I'll GLADLY take the 2.3 dB(A) hit with fan #3 in order to achieve that higher static pressure.

 

3 hours ago, Stahlmann said:

My guess is, that you guys never tried this fan. It's literally the best allrounder fan out there when it comes to noise to performance. It is specifically meant for radiator use and has good static pressure AND airflow.

Nope.  Wrong.  I have "tried" this fan (by tried, I mean actually used it and used very expensive lab equipment to measure it's characteristics) and have found it is the absolute worse fan on the market.  There's a reason why people haven't taken Noctua's fans and cloned them into cheaper variants... Because it's not worth it.  They're bad fans.

 

So let's, instead, get to the root cause of the problem as an RM650 should be the quietest PSU you can buy, and you even admit that in your previous build it was actually much quieter.  So why don't you tell us about your build?  What hardware?  RGB?   Where?  What case?  What's the orientation of the PSU in the case?

 

[Elisis]

1 hour ago, jonnyGURU said:

Because it's not worth it.  They're bad fans.

But muh SSO2! sigh

This stock replacement with Noctua shit seems especially rampant in SFFPC communities too, even with fucking FlexATX units, which is...

[Guest]

19 minutes ago, Elisis said:

But muh SSO2! sigh

This stock replacement with Noctua shit seems especially rampant in SFFPC communities too, even with fucking FlexATX units, which is...

I was ignorant once too.

 

About 20 years ago, I replaced the two 80MM fans in a 600W PSU I was using with these super quiet ones.  They had their own thermistor mounted to them that controlled fan speed and everything.  Two years later, all of the caps in the PSU were swollen and the PSU eventually died.

 

Unfortunately, we're dealing with a new generation that doesn't have the experience us old timers have.  To me, it was too long ago when Antec had a rash of failing True Power power supplies (2005?).  Why did they have a near 100% failure rate within the warranty period?  Because the fan profile was too relaxed (not enough static pressure) and it caused the extra crappy OST caps to swell up and explode.

[Elisis]

5 minutes ago, jonnyGURU said:

Unfortunately, we're dealing with a new generation that doesn't have the experience us old timers have. 

And it doesn't help that these people also deny there's a problem with doing so when informed, even if OTP were to keep tripping for them (if they're lucky).

[soldier_ph]

14 minutes ago, jonnyGURU said:

 

Unfortunately, we're dealing with a new generation that doesn't have the experience us old timers have. 

 

[Guest]

6 minutes ago, soldier_ph said:

 

I'm actually Gen X.  But that's still funny. 

[Guest]

43 minutes ago, Elisis said:

And it doesn't help that these people also deny there's a problem with doing so when informed, even if OTP were to keep tripping for them (if they're lucky).

OTP can be funny.  It only turns the PSU off if temperatures are critical.  The controller is programmed based on the fan the PSU ships with.  Even if the factory changes the fan, they have to reprogram the fan controller.  If the PSU is just cool enough to operate without tripping OTP, it's just going to slowly kill itself.

 

The Antec is an extreme example.  That was just a poorly designed PSU right off the bat.

 

[Stahlmann]

On 11/27/2020 at 8:54 PM, jonnyGURU said:

That is a terrible idea and ill conceived.  That's not a good fan for any PSU.

 

Let's look at these four examples:

 

All four of these fans are have the same hub diameter, same outer diameter, same fan frame and exact same motor.  Yet look at how different the fan blade design impacts their airflow (CFM), static pressure (mmH2O) and noise.  Remarkable, right?

That 29.7 dB(A) on fan #4 looks mighty tempting, and 64.7 CFM is a lot of air!  Would make a great intake or exhaust fan for a case, But I'll GLADLY take the 2.3 dB(A) hit with fan #3 in order to achieve that higher static pressure.

 

Nope.  Wrong.  I have "tried" this fan (by tried, I mean actually used it and used very expensive lab equipment to measure it's characteristics) and have found it is the absolute worse fan on the market.  There's a reason why people haven't taken Noctua's fans and cloned them into cheaper variants... Because it's not worth it.  They're bad fans.

 

So let's, instead, get to the root cause of the problem as an RM650 should be the quietest PSU you can buy, and you even admit that in your previous build it was actually much quieter.  So why don't you tell us about your build?  What hardware?  RGB?   Where?  What case?  What's the orientation of the PSU in the case?

 

If this fan is so bad, why has every other fan i tried before completely dissapointed me? I never found a fan that was this quiet while also running at the same temp target. I tried a few fans now and all the fans were noticeable louder when targeting the same water temp in my loop. In my case it's completely useless how good some fan design is at 2000RPM, because of my noise target my fans will never even hit much higher than 1000RPM. And you sould also know that a good fan at 2000RPM is not automatically good at lower RPM/noise levels. And the noctua fans are specifially designed to be the quietest possible at a set cooling performance, which they absolutely achieved with their NF-A12x25.

 

But i see your point, that each PSU is specifically designed with the fan they ship with in mind and changing it out would make no real sense.

[Guest]

14 minutes ago, Stahlmann said:

If this fan is so bad, why has every other fan i tried before completely dissapointed me? I never found a fan that was this quiet while also running at the same temp target. I tried a few fans now and all the fans were noticeable louder when targeting the same water temp in my loop. In my case it's completely useless how good some fan design is at 2000RPM, because of my noise target my fans will never even hit much higher than 1000RPM. And you should also know that a good fan at 2000RPM is not automatically good at lower RPM/noise levels. And the noctua fans are specifially designed to be the quietest possible at a set cooling performance, which they absolutely achieved with their NF-A12x25.

Maybe because you've never used any good fans?  Most case fans are cheap.  Heck.. even expensive fans don't necessarily have good fan blade design. 

 

Anyhoo... Let's get to the crux of your problem.  I asked what  your build is so why we can better understand why your RM650 is all of the sudden loud.  You've yet to answer that.  What's the top secret?

 

 

[Stahlmann]

14 minutes ago, jonnyGURU said:

Maybe because you've never used any good fans?  Most case fans are cheap.  Heck.. even expensive fans don't necessarily have good fan blade design. 

Then please tell me more about these fans you're talking about. I'm always interested in better fans for my specific usecase.

 

15 minutes ago, jonnyGURU said:

Anyhoo... Let's get to the crux of your problem.  I asked what  your build is so why we can better understand why your RM650 is all of the sudden loud.  You've yet to answer that.  What's the top secret?

Full specs are in my signature. But like i said, there is no "problem" per se. I just noticed that the PSU fan is the only fan i actually can notice. This is why is started this thread and now decided the idea is not worth it.

[akio123008]

29 minutes ago, Stahlmann said:

I just noticed that the PSU fan is the only fan i actually can notice.

Any fan on a power supply is automatically more noisy than any other, because it's placed at a 90 degree angle, blowing straight onto a PCB with very non-aerodynamic parts on it. Even if the fan itself produced 0 noise, it's airflow inside the power supply would. Casefans don't have this problem as much, as they usually have far more open space behind them.

[Guest]

Ok.  I tend to not expand people's signatures.

 

So a Lian-Li PC 011 Dynamic.  So the PSU fan is literally pointing right at the side panel so you can't help but hear it whenever it runs.  ANY PSU is going to be loud in that case.

 

Also, I used 2000 RPM as a reference point using the max RPM to show max CFM and pressure.

 

If you want a full report, it's going to take a lot more than a forum post to explain as each test report is an XLS with ten tabs.