Can I connect 3pin fans to a 4pin cpu fan header.

[game-source]

Hello,
I know this question has been asked before but no one gave a straight answer.
I know that 4pin fans can be controlled by software and by the cpu.
However I want to replace my current cpu fan on my Coolermaster T4 cooler.
I have 2 CoolerMaster Sickleflow 120 fans which are 3pin, I like them and are pretty silent, and I want to put them on the cooler for push-pull config. I also have a 3pin Y splitter and since I already have two fans unused I don't want to waste money and time to order other 4pin fans just to do a simple fan replacement.
My question is: Can I connect the two 3pin fans with the Y splitter and then plug the splitter into the 4pin cpu fan socket, so I can have both fans synced and controlled?
Since the other 3pin case fans I have installed are controlled by the mobo, can these two be also controlled?

 

[Supahos]

You can't control a 3 pin fan. That's what the 4th pin does. Yes it'll work however it'll just run full speed (or some set % of speed) at all times

 

[boosted1g]

Of course. THe motherboad is a 3 or 4 pin header, not ONLY 4 pin

 

[RARRAF]

connecting 3 pin fans to the 4 pin cpu cooler point will not work the reason the 4 pin header is there to control speed of the fan related to temperature of the cpu why make things so complicated order some 4 pin fans you will need them is my advice mind you I could be wrong.

 

[boosted1g]

You can't control a 3 pin fan. That's what the 4th pin does. Yes it'll work however it'll just run full speed (or some set % of speed) at all times

The motherbaord can still regulate the fan, just not quite as well as a 4 pin pwm fan.
Its not like it is bieng connected to molex to run at 100% all the time.

 

[Supahos]

I know, I was being a bit dramatic. But for a CPU fan I wouldn't want it running that way. Perfectly fine for case fans. But not on top of my CPU. Putting new fans may be quieter on that cooler but a push pull config on that CPU cooler will still perform poorly. Usually a push/pull config only adds 2-5% better cooling, works even worse if the fans aren't exactly the same speed it can actually hurt performance.

 

[boosted1g]

I know, I was being a bit dramatic. But for a CPU fan I wouldn't want it running that way. Perfectly fine for case fans. But not on top of my CPU. Putting new fans may be quieter on that cooler but a push pull config on that CPU cooler will still perform poorly. Usually a push/pull config only adds 2-5% better cooling, works even worse if the fans aren't exactly the same speed it can actually hurt performance.

Using a splitter they should be the same speed, but still a valid point.

If the OP is pushing his CPU hard, even more so if overclocking then should be spending the money the right 4 pin fans.
While you CAN use 3 pin fan and it will work, probably shouldnt for something as critical as cpu fan.

 

[Supahos]

A splitter doesn't ensure the same speed. Throwing identical voltages at two fans doesn't ensure identical speeds. Bearing efficiency/blade defects/dust/wiring issues in the splitter can all cause a 100-150 rpm difference. (Is this enough to drastically cause an issue? Answer is a solid maybe. Also the pull fan has air pushed on its back the same power being applied can actually run faster with the air pushing on it.

 

[JackNaylorPE]

The number of pins on a fan header are meaningless. Bit to know what you have, you have to read the MoBo Manual. On the fan side, 4-pin generally indicates PWM and 3-poin DCV. On the MoBo side, from a parts supply, inventory management, perspective, it's easier to just install 4 pin headers and use them for both 3 and 4 pin fans.

The Z87 generation of MoBos perfectly emphasized this approach. Most Z87 MoBos had all 4-pin headers, however while the CPU fans were PWM, the CHA fan headers were DCV. It appears that the "original" plan for Z87 was all PWM, as many MoBo manuals said exactly that, but at some point (after the manuals were written) manufacturers realized that this was not going to be possible for whatever reasons and put notices on their web sites.

With Z97 all but low budget MoBos have all 4 pin headers which can be used for either PWM of DCV speed control, most of them auto sensing.

The CPU does bot control fan speeds, the motherboard BIOS and / or provided software utility will.

PWMs advantage has been being able to control fan speeds down to lower rpms than DCV as when voltgae drops too low it can't "kick up" the fan from a dead stop. Recent designs have however overcome this disadvantage by applying a higher voltage at start up and then taking it down once the fan is spinning. PWM's disadvantage is low speed clicking / hum.

Phanteks came up with a design for their coolers which provided a little doodad that provided a best of both worlds scenario whereby controlled 3 pin DCV fans from a PWM signal. However, newer models have come with PWM fans, my guess being with the existence of the doodad ... it's a technical term ... PWM fan motor suppliers had to cut pricing to be competitive. The doodad not only chnaged the signal from PWM to DCV but was also a splitter to provide power to the two fans. Finally, it was able to provide low speed PWM like control to the 3 pin fans

What I would recommend for you is the Phanteks PWM to DCV (4-pin ==> 3-pn) fan hub. It splits the power and control from 1 PWM header to up to 11 fans and w/o the mess of splitter cables. You can use it w/o the supplied SATA power cable for up to 1 amp of power draw (about 6 x 140mm 1250 rpm fans) ... for more than 1 amp you will need the cable. It will take the PWM signal from the CPU header and distribute it to up to to (11) 3 pin fans.

http://phanteks.com/PH-PWHUB.html

 

[game-source]

Thank you all for the replies! I forgot to mention I have an Asus Z87m-PLUS Mobo. Sadly this device is nowhere to be found in my country 🙁
I can drop my plans for push pull and get a new fan.
What about this fan: Arctic F12 PWM, it's 4pin.
Is CFM that matters because this fan runs at 1350RPM with 24db noice and 74 CFM.
While my T4's fan is 1800RPM, 70CFM and 31db
Is it worth it? I want to reduce noise and increase efficiency and this looks nice.

 

[JackNaylorPE]

Noctua is generally accepted as having the best cooler on the market of any type w/ the NH-D15 ... yet if ya take the fans off a Noctua cooler and replace them with Phanteks fans at the same rpm, CPU temps drop a whopping 6C

http://www.overclockersclub.com/reviews/phenteks_f140/3.htm

In addition, SilentPCreview.com ranks Phanteks as the top fan in their testing

http://www.silentpcreview.com/article1345-page7.html

This was their top 20

Phanteks PH-F140HP/TS
Noctua NF-A14 FLX
Noctua NF-A15 PWM
Noiseblocker B12-2
Noctua NF-P14 FLX
Scythe Gentle Typhoon 120-12
Noiseblocker M12-S1
Corsair AF120 Quiet
Corsair AF120 Performance
Thermalright TR-TY150
Scythe Gentle Typhoon 120-14
Xigmatek XAF-F1453
Nexus Real Silent
Xigmatek XLF-F1453
Noiseblocker B12-PS
Corsair SP120 Quiet
be quiet! Silent Wings 2
Noiseblocker M12-S2
Antec TrueQuiet 120
Noiseblocker M12-P

As far as published fan specs, they are pretty much useless ... when they say 80 cfm @ 1.2 SP... that usually means
80 cfm @ 0. SP and 0 cfm at 1.2 SP ... In all likelihood that fan will run at 35-45 cfm at 0.8 SP

https://martinsliquidlab.wordpress.com/2013/02/18/why-static-pressure-max-flow-specs-are-poor-measures-of-fan-performance/

Your Mobo comes with:

1 x CPU Fan connector(s) (1 x 4 -pin)
2 x Chassis Fan connector(s) (2 x 4 -pin)

As indicated previously, w/ Z87, the 4-pin CPU fan headers were **usually** PWM and the 4-pin CHA fans were **usually** DCV.

So going forward ....

1. The Artic fan is a $20 fan ... there are better / cheaper alternatives

$15 - Phanteks PH-F120MP 120 mm PWM - 500-1800 ± 250 rpm 53.3 CFM, 25 dB (A)
https://www.newegg.com/Product/Product.aspx?Item=N82E16835709037

$16 - Phanteks PH-F120XP_BK 120mm PWM - 500 - 1500 ± 250 rpm 23.0 - 61.6 CFM 21 - 27 dB(A)
https://www.newegg.com/Product/Product.aspx?Item=N82E16835709034

$5 - If you want to use two fans on your cooler, grab one of these
http://www.performance-pcs.com/modmytoys-4-pin-pwm-power-distribution-pcb-4-way-block.html

 

[game-source]

From the website I buy my hardware from the Arctic F12 fan is 4-5 euro.. And the Noctua fans are really expensive here.. :/

 

[JackNaylorPE]

Noctua fans were not suggested. If ya tell us where "here" is, might be able to find a suitable recommendation for your area .

 

[JackNaylorPE]

connecting 3 pin fans to the 4 pin cpu cooler point will not work the reason the 4 pin header is there to control speed of the fan related to temperature of the cpu why make things so complicated order some 4 pin fans you will need them is my advice mind you I could be wrong.

That is simply incorrect. I would have agreed back in the 1990s but not here in 2017.

PWM fans are wired as follows:

1 = GND (black)
2 = +12VDC(yellow)
3 = Sense (green)
4 = Control (blue)

DCV fans are wired as follows:

1 = GND (black)
2 = +DC Voltage (red)
3 = Tachometric Signal Sensor (yellow)

PWM works by applying a constant 12V signal, but by turning the power on and off ... lengthening of OFF time to slow the fan down. The advantage of PWM *was* that you could get down to lower speeds because DCV fans at lower voltages could not start the fan from a dead stop whereas the full 12v signal from PWM could The disadvantage of PWM is a) low speed hum / clicking, b) cost and c) with some brands (i.e Corsair) , ganging too many fans on a single channel would result in loss of speed control.

The development of smart DCV fan controllers led to a best of both worlds scenario. Phanteks provided a little doodad on their coolers which converted the PWM signal to a modified DCV signal. It was capable of initiating fan start with a higher voltage and then tapering it down to low speeds, once the fan blade's inertia was overcome it could match PWMs low speed performance... and it also eliminated low speed hum. That technology was later incorporated into the Hub (PCB) which allows one to control up to 11 3-pin fans from a single PWM fan header.

When controlled in this manner, you get all the advantages of PWM fans and none of the disadvantages.

Today's motherboards (excluding very low budget models) have 4 pin headers and most will auto sense what type of fan is connected and control the fans accordingly.