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PWM help

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C

CROE

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Dec 2, 2015
I just installed water cooling for my computer as I wanted it to run quiet.

My thought was to have my pump controlled by my CPU_FAN-port, and my two case fans plus the three radiator fans controlled by the SYS_FAN1-port. But having everything installed and my computer on for the first time, I realised that this might not be possible as the fans require too much power.

My fans do not run when I have all five connected, but do run when I have four connected. I can not manage their speed through SpeedFan though either way.

Do I have to get a fan controller? I really do not want one as I have no 5.25" slot bay, and I did not find any controller with 4-pin either.

What are my choices? I have two 4-pin connectors on my mobo, one for CPU and one for SYS.

There was no problem with having three Noctua PWM-fans and managing them via SpeedFan. I now have two Noctua and three EKWB Vardar.
 
Speedfan? Yikes... ditch that old school program... just use the BIOS.

I would keep the power output to 12W/1A on the fan header otherwise you could overload it.
 
EarthDog said:
Speedfan? Yikes... ditch that old school program... just use the BIOS.

I would keep the power output to 12W/1A on the fan header otherwise you could overload it.
Click to expand...

BIOS? I don't know if I have PWM control there, I will go and check. My mobo is: MSI Z68A-GD65 (G3)
 
Not sure on that board. If it is a 4 pin fan header, then you should have PWM control. If it is 3 pin, then voltage.
 
EarthDog said:
Speedfan? Yikes... ditch that old school program... just use the BIOS.

I would keep the power output to 12W/1A on the fan header otherwise you could overload it.
Click to expand...

Nothing wrong with speed fan, sure it can be a pain to work with. But if your bios don't have a option to change the fans speed a old app like speed fan may still be able to change the fans speed.

but since OP is putting a pump on the cpu fan header he better use the bios and not a app. OP a pump could over load a fan header on the motherboard and kill it port. It could even take the board with it.
 
Nothing wrong with speed fan............."sure it can be a pain to work with" :rofl:

Being more serious, I would use it as a last resort only, Speedfan. It barely worked for me in 2005 so I ditched it then and used mobo software or a fan controller.

Depending on the pump, it may be powered from a molex/sata but controlled by PWM like a lot of AIO's are.

It would help to know what watercooling he used... :)
 
Okay, so I have two 4-pin headers, one for the CPU and one for the SYS. The CPU is for the pump, which also is running via molex.

I now managed to use BIOS as PWM control instead, which solved one of my problems.

The problems still remains with running all the fans, they will not run when connecting all of them to the SYS header. Two noctua and two EKWB Vardar is OK, but not one Noctua and three EKWB vardar. I guess the Vardar draws too much power.

Setup
Case: Fractal Design Define S
MB: MSI Z68A-GD65 (G3)
CPU: i5 2500k
RAM: Kingston HyperX 2x4GB 1600MHz
SSD: 2x Crucial BX100 250GB
GPU: 7950
PSU: EVGA G2 650w

Cooling
EKWB X360 KIT
EKWB GPU-block
EKWB fittings and angles
Koolance filter
Phobya taps
Destilled water and Biocide Extreme
 
Ok, so as suspected, there isn't a worry on that fan header... good. :)

If you look at the fans (so they are blowing at you), you should see a label on it that shows their output. I am guessing you are going over that 1A value?
 
EarthDog said:
Nothing wrong with speed fan............."sure it can be a pain to work with" :rofl:
Click to expand...
Yeah is can be a royal pain the the butt if the auto detect does not work. The bios/mobo software is much simpler.

EarthDog said:
Depending on the pump, it may be powered from a molex/sata but controlled by PWM like a lot of AIO's are.

It would help to know what watercooling he used... :)
Click to expand...
The kit he posted is using a EK-DDC 3.2 PWM Elite Edition pump, or that whats EK site says.
 
All the fans seem to require 0.12A in power, that would make it 0.66A... Right now I only have 2 fans active on my radiator (plus two case fans), which drive up the heat quiet good, about 50 degrees celcius playing GTA.
 
50c is fine for CPU Core temp, but I am curious why you can't get the 1 Noctua and 3 Vardar to run off the same header.

If all else fails just plug your Noctua case fans into a 3 pin fan header. They're quiet enough that even at full speed you won't notice them over your 7950.
 
Blaylock said:
50c is fine for CPU Core temp, but I am curious why you can't get the 1 Noctua and 3 Vardar to run off the same header.

If all else fails just plug your Noctua case fans into a 3 pin fan header. They're quiet enough that even at full speed you won't notice them over your 7950.
Click to expand...

Yeah, I guess, the fans is running 800 RPM and with only 2 of 3 radiator fans active.

What is working:
2 Noctua (120mm+140mm) + 2 Vardar = OK
2 Noctua (120mm+140mm) + 3 Vardar = NOT WORKING
1 Noctua (140mm) + 3 Vardar = NOT WORKING

Going to try:
1 Noctua (120mm) + 3 Vardar

Tried the Noctua 120mm with Low Noise Adaptor connected to a 3-pin header, but it runs too loud.. And even if it is OK noise-wise, 140mm Noctua + 3 Vardar will not work anyway. It looks like I need to have one Vardar connected to a 3-pin, but they are 1850 RPM (LOUD!) and the cable is too short, so it is not really an alternative. And PWM fans should not run on 3-pin, as it is really bad for the motors (from what I have read, they need a steady constant voltage).

The 7950 is in the water cooled loop, so I hope it doesnt make any noise, lol :D

Thanks for all the replys!
 
A 3 pin header still provides the same steady voltage (12v) until you tell it not to through Bios. The 4th pin on PWM is just the pulse signal.

I'm very Surprised that a Noctua hooked to a low noise adapter (800RPM IIRC) is to loud for you. I can barely hear mine with it at 100%
 
I'm wondering if the circuit that powers the fan headers is getting overloaded. Those vardars are 2.16w, and the noctua is a .48w fan. He might be putting too much load on the mb.
 
Blaylock said:
A 3 pin header still provides the same steady voltage (12v) until you tell it not to through Bios. The 4th pin on PWM is just the pulse signal.

I'm very Surprised that a Noctua hooked to a low noise adapter (800RPM IIRC) is to loud for you. I can barely hear mine with it at 100%
Click to expand...

Yeah, that's true, it's only bad for the PWM fan if I change the voltage (and RPM) via 3-pin.

I usually have it on around 500 RPM...

ikpthegame said:
I'm wondering if the circuit that powers the fan headers is getting overloaded. Those vardars are 2.16w, and the noctua is a .48w fan. He might be putting too much load on the mb.
Click to expand...

Where did you read that the Vardars have 2.16w?

My Vardars: 1.44w X 3
My 140mm Noctua 1.56w X 1
My 120mm Noctua 1.44 X 1

That should'nt be too much, right?
 
It was a review I found, and it was close it rpm. Could have been a older model, seeing as I couldn't get Ek's site to work on my phone. Idk you wouldn't think it is but you never know. It was just a thought seeing as when you have 3 vardars plugged in it don't work. I'd try them on the 3 pin and lower the voltage to slow them down.
 
ikpthegame said:
It was a review I found, and it was close it rpm. Could have been a older model, seeing as I couldn't get Ek's site to work on my phone. Idk you wouldn't think it is but you never know. It was just a thought seeing as when you have 3 vardars plugged in it don't work. I'd try them on the 3 pin and lower the voltage to slow them down.
Click to expand...

I guess that they draw too much power, as you said. But I really hope it isnt that, because then my only choice is to buy new ones, but I can't really use that kinda money right now.

I cant lower their RPM without PWM, as lowering voltage via 3-pin on a PWM-fan is not good, and it isnt really an alternative as I want all of my fans quiet via PWM.

The Noctua NF-F12 only draws 0.6w, and seems to be just as good as the Vardars, but they're 20€ a piece...
 
Blaylock said:
This is the answer you are looking for CROE.

http://www.amazon.com/Swiftech-8W-PWM-SPL-ST-Way-PWM-Splitter-Sata/dp/B00IF6R4C8
Click to expand...

Looks Great!

Can I run my pump from this splitter togheter with the fans, or can this damage the pump? I have read a few times that the pump should be directly connected to the CPU-header, without any splitter.

I have tried using a splitter with a molex and 5-PWM-connectors, this did not work, all the fans ran 100%. I only tried to connect to the SYS-FAN, though.

Is the splitter you posted any different from the one I have you think? Does sata vs molex matter?

Right now I use regular splitters without any PSU support. One 2-way from Noctua and one 3-way from EKWB to be exact.
 
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