Replacing the NZXT Kraken x40 stock fan with a silent one, crazy idea?

[Gremo]

I've brought a NZXT Kraken x40 AIO liquid cooler, for using with i7-4770K CPU. I can't still test the system as I'm waiting for components to arrive. I'd like to do some light overclock (possibly without touching voltages) because I want the rig to be very quiet, at least for the first months.

Here are the specs for the original NZXT Kraken x40 fan:

[b]NZXT FX-140 PWM[/b]
RPM: 800-2000 +/- 10%
Airflow: 91,7-166,9 m^3/h
Static Pressure: 0.8-2.2 mm-H2O
dBA: 21-37

Can I replace the stock fan with the NF-A14 PWM and still enjoy the software control for the fan itself and the pump (profiles, manual regulation, etc)? Fan is connected to the pump, will it work with a different fan?

It seems that the specs are quite comparable:

[b]NF-A14 PWM (no L.N.A.)[/b]
RPM: 300-1500 +/- 10%
Airflow: 140,2 m^3/h
Static Pressure: 2,08 mm-H2O
dBA: 24,6

More on this: I haven't brought the processor yet. Maybe i'll decide for a non-K one, as for me a stable, quiet and cool PC is more important than performance itself.

 

[Idontcare]

I don't have the hardware so I can't say with absolute certainty that it will work, but it definitely should work.

The fan controller has no way of knowing what fan has been plugged into the PWM fan header. All the fan controller does is send the PWM signal to whatever is plugged into the header.

So what will happen is that when you plug in your Noctua fan, even thought he Noctua can run as low as 300rpm the NZXT fan controller won't tell it to run that slow because the NZXT fan controller will have been programmed to assume the NZXT fan is plugged in and that fan has a minimum speed of 800rpm.

So your Noctua fan won't run any slower than 800rpm because that is the slowest PWM signal that the fan controller will be sending to the fan header.

Likewise the Noctua fan may "freak out" and stop spinning when the fan controller sends PWM signals for rpm's higher than the Noctua fan's max rpm of 1500.

The fan controller is going to think that it should send a 2000rpm PWM signal to the fan header when the NZXT controller thinks it needs maximum cooling capability from the fan. It isn't going to know that the Noctua fan itself can't handle the PWM signal cycling at that rate.

So what you really want is to find a PWM fan that spans the entire rpm range (min to max) of the NZXT fan - it can support lower and higher speeds (say 500-2500 rpm), so long as it supports the entire range - and has lower noise at any given rpm than the NZXT fan you are replacing.

xbitlabs has some great comprehensive fan reviews to find out what fans provide superior cooling/rpm and cooling/dB.

One thing you will find as a universal truth is that you pay for the priviledge of having the best fans in those metrics. Fans rapidly rise in cost from $5 to $10 and then upwards towards $30 (or more) per fan for the ones with the best cooling/dB.

http://www.xbitlabs.com/articles/coolers/display/120mm-fan-roundup-1.html

http://www.xbitlabs.com/articles/coolers/display/120mm-fan-roundup-2.html

http://www.xbitlabs.com/articles/coolers/display/120mm-fan-roundup-3.html

http://www.xbitlabs.com/articles/coolers/display/120mm-fan-roundup-4.html

 

[Sazuzaki]

as long as they use the same pins (if its PWM or 3pin) they should be able to control the fans.

 

[xD3aDPooLx]

Germo,

Any PWN fans will work. Like Idontcare stated above the software cant tell what fans are there. When you start touching the rpms with the program, it will turn any fan into a quiet one.

Once you got it all set up, take some pics. I want to see how it looks with those fans on it.

 

[crashtech]

I always thought PC PWM fans were fail safe, so that a maximum pulse width will just max out the fan, and never cause it to freak out.

 

[Idontcare]

I always thought PC PWM fans were fail safe, so that a maximum pulse width will just max out the fan, and never cause it to freak out.

Yeah you are right, it is the other direction that causes problems and the fan will just stop.

 

[crashtech]

Yeah you are right, it is the other direction that causes problems and the fan will just stop.

This has me wanting to learn a bit more ACPI specs for fan control. I don't even know if it is standardized, actually.

 

[Gremo]

First thank you people for helping me with this. I have to admin I'm still a lot confused.

So your Noctua fan won't run any slower than 800rpm because that is the slowest PWM signal that the fan controller will be sending to the fan header.

This is not a problem, Noctua fan should be barely audible at 800rpm. Good to know by the way.

Likewise the Noctua fan may "freak out" and stop spinning when the fan controller sends PWM signals for rpm's higher than the Noctua fan's max rpm of 1500.

This actually scares me. Since english is not my mother tongue, I can't fully understand how the above sentence relates to this (what do you mean for "other direction"?):

I always thought PC PWM fans were fail safe, so that a maximum pulse width will just max out the fan, and never cause it to freak out.

Yeah you are right, it is the other direction that causes problems and the fan will just stop.

Anyways we'll find it in a couple of days, I've brought 3 x NF-S12A PWM (for the case) and 1 x NF-A14 PWM (to be used with the radiator). See you soon

 

[Idontcare]

This actually scares me. Since english is not my mother tongue, I can't fully understand how the above sentence relates to this (what do you mean for "other direction"?)

My apologies for the confusing sentence. There is nothing to be worried about. The worst thing that can happen is the fan just stops spinning.

It won't be permanent, it would start spinning again as soon as the processor warmed up a little bit.

 

[Gremo]

Once you got it all set up, take some pics. I want to see how it looks with those fans on it.

Here we go, looks really nice I'm still waiting for the motherboard and choose RAM/CPU.

 

[xD3aDPooLx]

Looks different like that. I like it.

 

[crashtech]

Looks like it will move a decent volume of air, quietly.

 

[drclaw_]

Bump

I wanted to know if everything worked out for you, i have bought the same fan and wondered the same thing if the fan might stop working all a sudden,

i own the kraken x40 but im afraid to connect the fan to the coolers pwm

someone here mentioned the fan could stop spinning for a sec since the pwm on x40 is meant to jump to 2000rpm and the noctua 14 is capped at 1500.

I really want to replace the nzxt fan but if there is some risk to it ill just connect it to my mobo then and run a push pull config

 

[Gremo]

tltr: it will work and will keep your CPU cool and stay quiet most of the time.

Unfortunately I've just sold my Kraken X40 because the pump was too noisy for me. Pump speed is fixed, you have no control over it. Don't know if it was a problem of PWM connectors of my motherboard.

Btw I was completely unhappy with the product. Of course It was able to cool my i7-4770K very well, even under a light overvolt. But I've spent more than 150$ of noctua silent fans to make my rig quiet (at idle, at least) and the only noise came from the pump. The stock fan was also defective at 90% of its speed, making a very high and uncommon noise like blades hitting the mount itself (another user reported the same).

Anyways, to answer your question: yes, you can control your fan speed with the kraken control software. It will work.

However, to have more control over my rig with Asus thermal monitor software, I ended up.connecting the CPU (radiator) noctua fan directly to the motherboard PWM connector, thus not using the USB header at all.

 

[tweakboy]

IF your room temp is good like 74F then you can go silent ,,, But summer time you have to speed up the fan. gl