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PWM fan, connectors and CPU air cooler questions

Stargazer13
Go to solution Solved by LogicalDrm,
2 hours ago, Stargazer13 said:

1. My Corsair Carbide 400C case came in today. And I checked the fan pin connectors for the 120mm and 140mm fans that came with it and they are both 3 pins (Just 3 pins, not 4 pin with the 4th pin being a dummy pin). So since all of the fan headers on my board are 4 pins, where do I connect these 3 pin fans? They can't fit in the 4 pin headers can they? And if they do, how do I connect it to a 4 pin? And which header rod do I exclude? Here is the screenshot of my motherboard again just incase you need a reference:

 

You can connect 3pin to 4pin header and other way around. Though with some 3pin headers 4pin connectors just won't fit with plastic shroud. Those need some modding. Check this:

EikmD.pngconnector_mbfanpwm_4to3pin.png

 

So there's plastic tab to guide connector. You can't connect it wrong way without forcing it.

 

2 hours ago, Stargazer13 said:

2. How would you setup my fans? If you can go in detail on which fan to connect to which header and whether I should include or exclude the PWM fan hub that came with the Deepcool Assassin 2 CPU cooler. 

- x2 Deepcool Assassin 2 CPU cooler fans (Cooler kit included a PWM fan hub with 4 slots
- x2 140mm PWM Arctic fans (I plan on putting these two fans in the front)
- x1 Corsair 120mm fan for the back (Non PWM and only 3 pin. Came with the case)
- x1 Corsair 140mm for the top (Non PWM and only 3 pin. Came with the case)

Since you can use headers pretty freely. Use CPU fans on CPU_FAN header. I'm not sure if mobo uses different controller for each header or not. If it doesn't you need to connect same region fans to grouped headers. So front fans to one group (CHA_FAN1 and 2 for example). And rear+top to another (H_AMP and AIO, though manual is bit confusing whether they all have control or not). You need to do some testing to check what works best. Thats what PC  building is all about. Making it yours.

System Specs: (I just ordered the compoments so I don't have them yet)
Case: Corsair Carbide 400C White
Motherboard: Asus Z270-A
CPU: Core i-5 7600k
GPU: Gigabyte GTX 1070
PSU: EVGA Supernova G3 750 PSU
CPU Air Cooler: Deepcool Assassin 2
Memory: 16GB (x2 8GB Stick) Corsair Vengence LPX
SSD: Kingston V300 240GB
 

 

 

Greetings LTT community,

 

I haven't built a PC system for a long time, but I will be building one soon, and I have a few questions:

1. I understand PWM fans can be automatically controlled by the motherboard. The motherboard will adjust the speed accordingly in relation to the CPU and GPU temperatures.

1a. So to set these PWM fans to run in PWM mode, I have to go into the BIOS to set it. What I don't understand is, why there's multiple options for the fan speed when the motherboard is suppose control the PWM fans. Here is a screenshot:

http://imgur.com/a/2Mp1v (The screenshots aren't of my system)

2b. What does DC mode do? Is it for none PWM fans with 4 pin connectors? 

3c. Now I read PWM fans are mainly for fan control. But none PWM fans can already be controlled from the BIOS, right? So what's he difference between PWM and none PWM fans if both fan types can be controlled?

4d. I've read that the only true PWM controlled 4 pin header on the motherboard is the CPU Fan header? The rest of the 4 pin headers on the motherboard are controlled in DC mode. I have no idea what this means. If someone could clear this up for me. So there's only one 4 pin header where you can actually run fans on PWM mode?


2. As you can see above, I purchased the Deepcool Assassin 2 CPU air cooler and I have a few questions:

2a. The two PWM CPU air fans connects to the PWM Deepcool fan hub. Then the Deepcool fan hub connects to the motherboard (In my case the Asus Prime-A). Where on my motherboard would I connect the Deepcool fan hub into? The CPU_FAN header? Here's a screenshot:

http://imgur.com/a/irIPg

2b. If you look at the screenshot below, it shows step 12, 13 and 14. I think 12 is showing the two PWM fans being connected to the hub. For step 13 it looks like the removal of a sticker or film from the rectangular piece? And for 14 I have no idea. Does anyone know?

2c. The Corsair Carbide 400C case only comes with x1 140mm front intake fan and x1 120mm back exhaust fan. I want to order x2 ARCTIC F14 PWM Rev.2 PWM fans. So I could connect these two PWM fans to the Deepcool fan hub? And these 2 Arctic fans would be controlled together with the 2 Deepcool PWM CPU fans?

2d. I read somewhere that connecting too many fans on the motherboard will put stress on the motherboard. Is this true? If so then should I connect the 2 extra Arctic PWM fans straight to the PSU?

2f. Where do I connect the 2 case fans that come with the The Corsair Carbide 400C case? Do I connect it to the PSU or to the board? What are the differences from the two? I can't figure out if the these two case fans are 3 or 4 pin. It doesn't say. Here is a screenshot:

http://imgur.com/a/juKbD

2g. If you connect a 4 pin fan to the PSU by connecting it to a molex 4 pin cable, can you control the fans from the BIOS? Or does it just run at full speed automatically without you having any control?

3. Last question. I just need to confirm that the two case fans in front will be intake fans (suck in cool air), and the one fan I'll put on top and one on the back are exhaust fans (suck out hot air). Because in this video, the guy says the top fans are sucking in air into the case. So that video kind of confused me. Just need to make sure I was right. Here is the video:
https://www.youtube.com/watch?v=MUFOvLEX1Sc


That's all the questions I have for now. It's a lot of questions and I hope I'll be able to find answers here. Thank you all!

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4 hours ago, Stargazer13 said:

1. I understand PWM fans can be automatically controlled by the motherboard. The motherboard will adjust the speed accordingly in relation to the CPU and GPU temperatures.

Most of the times its only by CPU. I'm not sure if Asus allows GPU temps to be used yet. But you can do that with Speedfan.

 

4 hours ago, Stargazer13 said:

1a. So to set these PWM fans to run in PWM mode, I have to go into the BIOS to set it. What I don't understand is, why there's multiple options for the fan speed when the motherboard is suppose control the PWM fans. Here is a screenshot:

PWM vs DC is how mobo is supposed to control fans. If you set it to PWM, you can't control DC/3pin fans from that header. And other way around.

 

The options you see are preset profiles. You can use one of them, or select manual and set curve yourself.

 

4 hours ago, Stargazer13 said:

2b. What does DC mode do? Is it for none PWM fans with 4 pin connectors? 

Yes and no. 4pin fans ARE PWM fans. 3pin fans are DC fans. DC means that mobo will read rpm and supply voltage according to what % of rpm is set. PWM means that mobo will supply fan with PWM cycles via 4th pin. Fan gets full 12V all the time, but speed is set with cycles. Which means any 3pin fan used from that header can't be controlled and will run at full speed.

 

4 hours ago, Stargazer13 said:

3c. Now I read PWM fans are mainly for fan control. But none PWM fans can already be controlled from the BIOS, right? So what's he difference between PWM and none PWM fans if both fan types can be controlled?

What happened to 3, 3a and 3b? Joking.

 

3pins can be controlled. And can be controlled from BIOS. But not all mobos have support for it. Like mine doesn't have native support for 3pin control so I use Speedfan. Difference, like I've said already in this post, are that 3pins are controlled by changing supplied voltage based on % of max rpm (or max volts, I'm not sure). PWM fans run at full 12V all the time and controlling is done by PWM cycles.

 

4 hours ago, Stargazer13 said:

4d. I've read that the only true PWM controlled 4 pin header on the motherboard is the CPU Fan header? The rest of the 4 pin headers on the motherboard are controlled in DC mode. I have no idea what this means. If someone could clear this up for me. So there's only one 4 pin header where you can actually run fans on PWM mode?

This depends on mobos. All modern mobos have at least 1 true PWM header and that is CPU_FAN. This is true. But some of most recent mobos also have other headers providing PWM controls. While specs don't tell this (you can see specs claiming x amount of 4pin headers), you can check mobo and see which headers have PWM.

 

All 4pin headers on your mobo are true PWM headers. Manual page 1-19.

 

4 hours ago, Stargazer13 said:

2a. The two PWM CPU air fans connects to the PWM Deepcool fan hub. Then the Deepcool fan hub connects to the motherboard (In my case the Asus Prime-A). Where on my motherboard would I connect the Deepcool fan hub into? The CPU_FAN header? Here's a screenshot:

You need to connect some fan to CPU_FAN header anyway. And from the looks of it that hub works like splitter. Each mobo header can power 3-4 fans, so just use CPU header.

 

If you are wondering why 3-4fans. Its about how much amperage header provides and how much fans use. Headers are 1A, fans use 0.2-0.4A.

 

4 hours ago, Stargazer13 said:

2b. If you look at the screenshot below, it shows step 12, 13 and 14. I think 12 is showing the two PWM fans being connected to the hub. For step 13 it looks like the removal of a sticker or film from the rectangular piece? And for 14 I have no idea. Does anyone know?

The numbers reference to part listing at the beginning of manual. Part 14 is cable tie or zipt ie.

 

4 hours ago, Stargazer13 said:

2c. The Corsair Carbide 400C case only comes with x1 140mm front intake fan and x1 120mm back exhaust fan. I want to order x2 ARCTIC F14 PWM Rev.2 PWM fans. So I could connect these two PWM fans to the Deepcool fan hub? And these 2 Arctic fans would be controlled together with the 2 Deepcool PWM CPU fans?

Yes and yes. Though, if you want to use different fan curves to different fans, you need to use different headers. Header will use only one fan curve and all connected fans follow that curve.

 

My suggestion would be using CPU fans and maybe exhaust fans on hub and have intakes run on their own. You can get Y-splitters to have more than one fan per header.

 

4 hours ago, Stargazer13 said:

2d. I read somewhere that connecting too many fans on the motherboard will put stress on the motherboard. Is this true? If so then should I connect the 2 extra Arctic PWM fans straight to the PSU?

See above about amperage. If you have PWM fans, connecting them to PSU will defeat purpose of them being PWM. You can't control fans connected to PSU. You can connect more than 3 fans to mobo header by getting powered hub. This means hub will get power for fans directly from PSU and control will come from mobo.

 

4 hours ago, Stargazer13 said:

2f. Where do I connect the 2 case fans that come with the The Corsair Carbide 400C case? Do I connect it to the PSU or to the board? What are the differences from the two? I can't figure out if the these two case fans are 3 or 4 pin. It doesn't say. Here is a screenshot:

You have enough headers to connect all fans to them. If you can, don't connect to PSU. See above why. Most of the case fans are 3pin.

 

4 hours ago, Stargazer13 said:

2g. If you connect a 4 pin fan to the PSU by connecting it to a molex 4 pin cable, can you control the fans from the BIOS? Or does it just run at full speed automatically without you having any control?

First, you need adapter between fan 4pin and molex 4pin. And yes, like said above, all fans connected to PSU will run at full speed (unless you use resistor/low-noise adapter) and can't be controlled.

 

4 hours ago, Stargazer13 said:

3. Last question. I just need to confirm that the two case fans in front will be intake fans (suck in cool air), and the one fan I'll put on top and one on the back are exhaust fans (suck out hot air). Because in this video, the guy says the top fans are sucking in air into the case. So that video kind of confused me. Just need to make sure I was right. Here is the video:

Top fans on the video are set to intake. But he's also using down-draft cooler which benefits from that setup. For you its better to have front intakes and rear/top exhausts. You would be just fine by having 2 intakes and 1 exhaust.

 

4 hours ago, Stargazer13 said:

That's all the questions I have for now. It's a lot of questions and I hope I'll be able to find answers here. Thank you all!

Np, thats why these forums exist. And if you reply by quoting me, press Enter two times to break quote. Makes helping on specific problems much easier.

^^^^ That's my post ^^^^
<-- This is me --- That's your scrollbar -->
vvvv Who's there? vvvv

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Thanks for the great explanation LoGiCalDrm, I appreciate it. I have a couple more questions for you or anyone else reading this:

 

1. My Corsair Carbide 400C case came in today. And I checked the fan pin connectors for the 120mm and 140mm fans that came with it and they are both 3 pins (Just 3 pins, not 4 pin with the 4th pin being a dummy pin). So since all of the fan headers on my board are 4 pins, where do I connect these 3 pin fans? They can't fit in the 4 pin headers can they? And if they do, how do I connect it to a 4 pin? And which header rod do I exclude? Here is the screenshot of my motherboard again just incase you need a reference:


http://imgur.com/a/irIPg

2. How would you setup my fans? If you can go in detail on which fan to connect to which header and whether I should include or exclude the PWM fan hub that came with the Deepcool Assassin 2 CPU cooler. 

- x2 Deepcool Assassin 2 CPU cooler fans (Cooler kit included a PWM fan hub with 4 slots
- x2 140mm PWM Arctic fans (I plan on putting these two fans in the front)
- x1 Corsair 120mm fan for the back (Non PWM and only 3 pin. Came with the case)
- x1 Corsair 140mm for the top (Non PWM and only 3 pin. Came with the case) 

Thanks again for the help!

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2 hours ago, Stargazer13 said:

1. My Corsair Carbide 400C case came in today. And I checked the fan pin connectors for the 120mm and 140mm fans that came with it and they are both 3 pins (Just 3 pins, not 4 pin with the 4th pin being a dummy pin). So since all of the fan headers on my board are 4 pins, where do I connect these 3 pin fans? They can't fit in the 4 pin headers can they? And if they do, how do I connect it to a 4 pin? And which header rod do I exclude? Here is the screenshot of my motherboard again just incase you need a reference:

 

You can connect 3pin to 4pin header and other way around. Though with some 3pin headers 4pin connectors just won't fit with plastic shroud. Those need some modding. Check this:

EikmD.pngconnector_mbfanpwm_4to3pin.png

 

So there's plastic tab to guide connector. You can't connect it wrong way without forcing it.

 

2 hours ago, Stargazer13 said:

2. How would you setup my fans? If you can go in detail on which fan to connect to which header and whether I should include or exclude the PWM fan hub that came with the Deepcool Assassin 2 CPU cooler. 

- x2 Deepcool Assassin 2 CPU cooler fans (Cooler kit included a PWM fan hub with 4 slots
- x2 140mm PWM Arctic fans (I plan on putting these two fans in the front)
- x1 Corsair 120mm fan for the back (Non PWM and only 3 pin. Came with the case)
- x1 Corsair 140mm for the top (Non PWM and only 3 pin. Came with the case)

Since you can use headers pretty freely. Use CPU fans on CPU_FAN header. I'm not sure if mobo uses different controller for each header or not. If it doesn't you need to connect same region fans to grouped headers. So front fans to one group (CHA_FAN1 and 2 for example). And rear+top to another (H_AMP and AIO, though manual is bit confusing whether they all have control or not). You need to do some testing to check what works best. Thats what PC  building is all about. Making it yours.

^^^^ That's my post ^^^^
<-- This is me --- That's your scrollbar -->
vvvv Who's there? vvvv

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Thanks again for the explanation LoGiCalDrm. Very informative!

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