Motherboard PWM fans problem
Motherboard PWM fans problem
Hello, your recent PWM fans and controller seem to be working fine, but the MSI H110M PRO-VD has a llimit of 5 PWM fans. When you add the sixth one, it operates at full speed. Can you try to find a way around that restriction? Additionally, you're considering the GIGABYTE Z690 AORUS MASTER. Does this model have the same limitation, and if yes, are there options to work around it?
It's tough to judge without knowing your fan controller. Still, why not just use a PWM splitter?
I used the ARCTIC ACFAN00175A controller. After connecting it directly to SYSFAN1 on the motherboard, all fans spun at full speed (I made sure a fan was connected to port 1 on the controller). When I noticed this, I switched case PWM ports into SYSFAN1 and then connected the ARCTIC controller to one of those ports. It functioned properly, except for five fans which remained at full speed. I wondered if a PWM splitter would have been better, but my case (Fractal Define 7) only has four PWM ports, while I needed eight. I opted for the ARCTIC controller with ten ports instead.
Hm that is strange. Does not compute, unless I'm missing something or if there is something wrong with the hub. You have 8 chassis fans yes? and 2 fan controllers both PWM (in other words 4-pin) and mobo can do 5 (I'm guessing 3 plus CPU and CPU optional)? Also both hubs have SATA power? 1. If you only use CPU and and a SYSFAN header on the mobo for CPU and disconnect the Fractal one, some fans are controlled correctly while some go full speed? 2. If you populate all SYSFAN headers with fans and Arctic controller the same happens? 3. If you use the Fractal hub and disconnect the Arctic one what happens then? 4. If you don't use any of the fan hubs and only put fans on your mobo headers will they work as expected? 5. Does your BIOS or other fan control software let you choose between PWM and DC modes? If so try PWM.
I have eight fans and two PWM controllers. One is integrated into the case, with four 4-pin connectors on the back and powered via SATA. The second cable connects to SYSFAN1, which has always functioned correctly.
I haven't yet tried connecting it from SYSFAN to the CPU.
I'm uncertain if that's what you were asking, but I only had one SYSFAN port on the motherboard.
It operates as expected, but removing the Fractal hub and using only the Arctic one causes it to fail, even though BIOS settings remain unchanged. To resolve this, I need to connect the Arctic hub to the Fractal one.
I can only use one fan at a time, but I haven't tested that yet.
It was already configured in BIOS and worked fine with the Fractal hub before.
Do motherboards typically have such restrictions on PWM fans? I'm not sure how this will affect the new motherboard.
Additionally, I'm curious—does this situation occur often? Are there known limitations on the number of PWM fans supported by different boards?
I hope this helps clarify things.
I thought you might have more fan headers on the motherboard. I looked at another version or revision of your board that includes 3+1 headers. Now we’re sure the problem isn’t with the motherboard header at least because the fractal is working. Regarding the cable to the Arctic hub, it gets power from the SATA connector since drawing all current from that would damage the PWM header. That’s likely why it only has two cables. I’d think about just sending back the Arctic hub and using fan splitters on the Fractal hub. It has four headers and supports eight fans. I don’t believe you’ve made a mistake, but the fact it doesn’t function properly when plugged directly into the motherboard suggests there could be a bigger issue with the hub. Fan splitters seem like a quick fix, but a replacement Arctic fan hub might be better if needed.
@aDoomGuy Hello, I don't know if you're still there, but I got one last question. Do even motherboards have any limit of how many PWM fans can be plugged in no matter in which way? Because I've heard that it's possible to overload fan header when you don't have a hub that is powered via SATA or something else. Edit: after some googling I found this: How many fans can be connected to a PWM? Example: If a fan has a current strength of 0.2 Ampere and the motherboard fan connector has 1 Ampere, up to 5 fans can be operated in series via PWM Sharing Technology. So I guess there's no way to plug more than 5 PWM fans?
Sure, I'm here. Fan headers do have a limit on the number of fans that can be connected. Typically, I avoid linking more than two fans at a time. The exact number safe varies by fan model and header design—not all are the same. If you connect just two fans, it should be fine unless they're very powerful. Five fans is pushing the limit; if they're max out to 0.2, I'd cap it at four per header. The fractal design hub does have a SATA connection, so you shouldn't worry about having four headers. You can safely connect up to eight fans without issues, as the hub doesn't draw power from the headers. The CPU fan header can also share with another fan, allowing up to ten fans if you connect two per header. If you need more, consider hubs with internal USB ports on your motherboard.