Proper fan configuration?

BigBuckBunny · April 22, 2015

Hello! I am planning on buying a Fractal Design Define R5. It will house a VII Hero, an i7-4790K @ 4.5GHz (at the moment), an Asus GTX970, 16 GB of Corsair Vengeance, a Samsung DVD drive (Yeah, I still need one), 2 SSDs (Windows and Linux), a shared 2 TB drive (1.5/0.5 share - backup is done via an external harddrive and Dropbox, don't worry) and a Cooler Master Silent Pro M2 620W (from previous build). The only thing bothering me is the cooling. The R5 is made for silence, so I'd like to keep it rather quiet. I know, there are quieter possibilities than an X61 - I just wanted to try it for once. Anyway, I was planning on removing the HDD cages, install the ODD and the HDD in the ODD cage (the HDD via this guy) and the two SSDs at the back of the motherboard, feeding them with a molex --> 2x sata splitter, since one stealth mount costs me an entire sata-powercable. The X61's radiator would be mounted at the front, cooled by two Noctua NF-A14 PWM fans. Another NF-A14 PWM would do the exhaust at the back of the case, keeping the top and side moduvents closed. I will use the on board Asus fan controller, since there's no AI Suite or CAM for Linux. Speaking of which, what does the CPU_OPT header exactly do? Is it linked to the CPU_FAN or is it possible to use CPU_FAN for the pump and the CPU_OPT with a y-splitter for the who intake fans?

This configuration of 2x 140mm intake and 1x 140mm outtake feels like it isn't enough, since it has to cool the mosfets and GTX970 as well. However, it does create a positive pressure inside of the case and that makes me think it should be okay.

What do you guys think about this? If it makes some noise when in full load, then that is no problem. However, it should be rather quiet when idling.

Worldinc · April 22, 2015

Yes you should plug in your pump in CPU_FAN and use a Y splitter to plug both fans into CPU_OPT. I ran this setup in a Define R4 and it was fine. It will be super silent

ThomasD · April 22, 2015

The ASUS suite lets you set fan profiles for each motherboard header.

So, you can also plug the AiO fans into CPU_FAN and CPU_OPT, then plug the pump into another header - FAN_2, or whatever. Most pumps are supposed to be run at 100% all the time, and I understand the X61 is different and allows for slower speeds, but it is also my understanding that you still want the header at full power and then the control is managed from the device.

I think your overall temps will be Ok, especially with the 970, but with the radiator in front you are bringing heat back into the chassis, so do have the potential for a positive feedback loop. On the plus side it should be very quiet. Just don't put the rear of the chassis too close to a wall, one it will restrict airflow and two it will reflect noise.

If you try that set up and temps are higher than you'd like I'd first add a bottom intake fan, and then if necessary a top exhaust.

BigBuckBunny · April 23, 2015

Yes you should plug in your pump in CPU_FAN and use a Y splitter to plug both fans into CPU_OPT. I ran this setup in a Define R4 and it was fine. It will be super silent

Were you able to set the fan curves in the UEFI, when you did that?

The ASUS suite lets you set fan profiles for each motherboard header.

So, you can also plug the AiO fans into CPU_FAN and CPU_OPT, then plug the pump into another header - FAN_2, or whatever. Most pumps are supposed to be run at 100% all the time, and I understand the X61 is different and allows for slower speeds, but it is also my understanding that you still want the header at full power and then the control is managed from the device.

I think your overall temps will be Ok, especially with the 970, but with the radiator in front you are bringing heat back into the chassis, so do have the potential for a positive feedback loop. On the plus side it should be very quiet. Just don't put the rear of the chassis too close to a wall, one it will restrict airflow and two it will reflect noise.

If you try that set up and temps are higher than you'd like I'd first add a bottom intake fan, and then if necessary a top exhaust.

I know the UEFI lets you set them, but I thought maybe CPU_OPT was linked to CPU_FAN; CPU_OPT mirroring CPU_FAN. But I take it that's not the case then.

The X61 indeed allows for different speeds, but since it'll start rattling when at <12V, it's already running at 12V constantly. I've simply set this in the UEFI, otherwise I get a lot of noise when in a Linux OS. No drivers...

Regarding the fan setup: I talked about it with my old man and he prefers an under pressure (is this the correct term? Less intake than out take, a lower pressure inside of the chassis than around it) so it'll always suck in fresh and cold air. Downside is the dust it takes with it. I get that putting the rad on top of the case will make it quieter, but will it generate a lot more noise? In idle I know I only need to power the two radiator fans to be okay at about 30 degrees Celsius. I have taken a look at reviews of the X61 and the specs of the fans and as it turns out, the Noctuas deliver a higher static pressure (which one wants on a radiator, right?) at a lower RPM: 2,08 mm H₂O at 1500 RPM for the Noctuas and 1,97 mm H₂O at about 2000 RPM for the NZXT. Looking at decibels, the NF-A14 is at max speed about 24,6 dB(A) whereas the NZXT is about 37(!) dB(A). However, the Noctua has an airflow of 83 cf/m but the NZXT 106,1 cf/m. I must say I am taking the manufacturer-given specs now since the NF-A14 PWM hasn't been reviewed anywhere properly yet, as far as I have found.

Say I'd like a quiet setup when needed, but also a cool setup when needed: Would it be a better idea to go for an all out Noctua config (I don't care about how they look) with the rad at the top and only let the two radiator mounted fans spin in idle, or should I use the NZXT fans do the input since they have a better airflow passing through them? Any ideas would be greatly appreciated!

ThomasD · April 23, 2015

snip

Not sure, but I think both CPU headers operate as one. And I think you can also access the fan control settings without having to drop intot he UEFI - they are accessible from the ASUS Suite program.

Personally I think it better to have a radiator venting to the outside. Even if the air inside the case is warmed by the other components the delta (ability to transfer heat) of the radiator will not be reduced all that much, and can also be assited by ensuring a large volume of air coming into the case.

Exactly what fans you choose depends on your budget. I'm extremely skeptical of manufacturer specs. Once you place them in less than ideal circumstances, or working with any other fans those figures tend to go out the window. That said I do have a couple Noctua 14cm fans are they are quiet compared to others I have from NZXT, Corsair and Thermaltake.

Given what you desire I'd look at adding as many chassis fans as you can tolerate/afford. Brand name and/or dB not being as critical as cfm, as I'd have the AI Suite run them all at minimal speed until temps got fairly high - then ramp them up abruptly for maximum effect. It is expensive, but a large number of fans turning slowly can move a tremendous amount of air very quietly, so temps should stay down except under extreme gaming.

BigBuckBunny · April 23, 2015

Not sure, but I think both CPU headers operate as one. And I think you can also access the fan control settings without having to drop in tot he UEFI - they are accessible from the ASUS Suite program.

As stated in the fipo, I use Linux quite a lot and there's no AI Suite in Linux. Therefore I have to use the UEFI version, because my pc is noticeably louder in Linux than in Windows.

Come to think of it, it's possible the lack of CAM and not of AI Suite is the reason. I'll have to take a look at that.

Exactly what fans you choose depends on your budget. I'm extremely sceptical of manufacturer specs. Once you place them in less than ideal circumstances, or working with any other fans those figures tend to go out the window. That said I do have a couple Noctua 14cm fans are they are quiet compared to others I have from NZXT, Corsair and Thermaltake.

The Noctua NF-A14 PWM fans are within budget. I have been looking at the NF-A14 iPPC-2000 PWM version, but I think that's overkill.

Given what you desire I'd look at adding as many chassis fans as you can tolerate/afford. Brand name and/or dB not being as critical as cfm, as I'd have the AI Suite run them all at minimal speed until temps got fairly high - then ramp them up abruptly for maximum effect. It is expensive, but a large number of fans turning slowly can move a tremendous amount of air very quietly, so temps should stay down except under extreme gaming.

After some calculations (some manufacturers only give m³/h, others only cf/m), I found the following (again looking at manufacturer's specs):

Fractal Design Dynamic GP-14:          68.4 cf/m / 116.2 m³/h @ 1000 RPM (18.9 dB(A))        Note: Only 3-pin fan in the table.Noctua NF-A14 PWM (w/o L.N.A.):        83.0 cf/m / 140.2 m³/h @ 1500 RPM (24.6 dB(A))Noctua NF-A14 industrialPPC-2000 PWM: 107.4 cf/m / 182.5 m³/h @ 2000 RPM (31.5 dB(A))NZXT FX V2 140mm:                     106.1 cf/m / 180.3 m³/h @ 2000 RPM (37.0 dB(A))

The Dynamic GP-14 fans come with the Define R5 and the FX V2 come with the Kraken X61, that's why they are included. I used a well known website to compare fans and came to the conclusion that the NF-A14 PWM indeed are the most suitable fans. I do not care about the colour scheme because I won't be looking at it that much. The current plan is to get five of these fans and let them run nice and slow, as you said above. And yes, I know it's expensive, but I want this PC to last at least 5 years and with my current specs that must be possible. The NF-A14s coming with a y-splitter is another welcome thing. This would allow me to let the two intake and radiator fans run at about the same speed.