[SOLVED] Fan splitter, or hub? Gigabyte A520M DS3H

[King_V]

So, the one shortfall to the motherboard that I'm seeing right now is a dearth of fan headers. One for CPU, and two for SYS (one near the rear, one near the front).

My case comes with 3 fans, one rear, two front. Unfortunately, they are 3-wire fans, so, I'm assuming voltage-controlled speed. I am considering adding a 3rd fan to the front, if needed. I might also replace all the fans with 4-wire PWM models.

The manual, at page 32, seems to indicate that the MB will be able to automatically determine if it's voltage vs PWM, so I think I'm good there.

Am I safe using a splitter, or is a hub the way to go? Any particular recommendations for either? If an externally powered hub, ideally one that'll take a SATA power cable instead of a molex relic.

 

[Lutfij]

The header might be able to manage the fans regardless of PWM or DC but the issue stems from the PWM hub/splitter end. If you have a 3pin fan on a PWM splitter or hub, the fans tend to run at full blast. The only exception I've found with regards to fan hubs is the one made by Phanteks, here, have it on my Phanteks Enthoo Evolv ITX build and the hub will work with 3pin fans or PWM fans and they will all behave the same.

If you replace all the fans, this is a good time to get all PWM fans and that won't limit your choices for PWM hubs or splitters.

 

[DRagor]

For just 3 fans I would use splitter as long as all 3 fans are same model and rated at no more then 0.3 A. You have not mentioned case model so hard to tell if those fans supplied with case are any good, but the option to just remove them and get 3 PWM fans instead sounds good anyway.

 

[logainofhades]

I use this hub, in my personal rig.

https://www.amazon.com/SilverStone-System-Cables-Black-CPF04/dp/B00VNW556I

 

[King_V]

Ah . .the case is an Antec P7 Neo. I haven't even gotten a look in the case yet, really. Time/real-life getting in the way.

I do have two beQuiet Pure Wings 2 120mm fans, and two of beQuiet Pure Wings 2 140mm, all 4 pin, which I might switch to. But the case is supposed to be known for being quiet, so I imagine the included fans were chosen with that in mind. Or maybe I'm being optimistic in how Antec chose the included fans.

There's three headers total, but one is for the CPU. One SYS fan header at the back, and another at the front.

 

[Paperdoc]

Background first. You are right. If those fans have only three wires from them ending in a female connector with 3 holes, you can ONLY control their speeds by altering the VOLTAGE supplied to them from the mobo header, Now, with one exception, a HUB can NOT do that. BEWARE - makers of Hubs and Splitters misuse those two labels and mix them badly. To me, a SPLITTER is the simple device that just connects all its fans in parallel to the pins of the mobo header so all fans receive the same signals, and ALL power for the fans comes solely from the header. It has one input "arm" that connects to a mobo header, and two or more output "arms" for plugging in fans. But note that it may LOOK like a collection of cable arms, or like a circuit board, or like a box with ports inside holes in the box. A HUB is a different device that has those same features and appearance, but has an EXTRA "arm" that must plug into a power supply output from the PSU (either Molex or SATA). A Hub does NOT take power for the fans from the header - it gets power directly from the PSU - so it avoids the normal limit of 1.0 A max current draw from a header. The Hub distributes the PWM signal from the header to all its fans. BUT this means that the HUB can control the speed ONLY of 4-pin fans, and it MUST have a PWM signal from a header using the new PWM Mode of signals to its fans.

OP, for your situation with 3-pin fans, the only way is to use a SPLITTER which can distribute to its fans the VOLTAGE the the mobo header supplies - it is varied to change fan speed. BUT that means the the total current draw of all the fans on one header cannot exceed the limit of 1.0 A max. Normally that is not a problem - most fans today draw at max from 0.10 to 0.25 A, so two or three on one header via a Splitter is OK. But you should CHECK the fan labels for the max current rating. This is especially important for you! The web page for that case mentions some LED lights, but does NOT make it clear whether there are lights in the frames of the fans supplied. There was an early design of lighted fans called LED Fans in which there was only ONE colour of lights, and ONE power cable to the fan, and the lights were just wired in parallel with the motor so they light up when the fan is running. (New RGB and ARGB Fans are different.) These older designs use more power than a plain fan, although not usually over 0.45 A per fan so that two such fans on one header was still OK. But be sure to CHECK before proceeding.

So, assuming you need to connect only three such fans to two headers by using ONE Splitter for one pair, it is very likely that will work, whereas a HUB can NOT do the job. A simple Splitter is like

https://www.amazon.com/JBtek-Black-...1646243277&sprefix=fan+splitter,aps,91&sr=8-8

That's a 2-pack of 4-pin Splitters, but you CAN use them for 3-pin fans, and you only need one of them. Another design looks like a circuit board

https://www.amazon.com/Splitter-Sle...1646243361&sprefix=fan+splitter,aps,91&sr=8-9

You are partly right about your mobo's ability to do this. See its manual, p. 32, for the details of how to configure the fan headers in BIOS Setup. For EACH header set the Fan Control Mode to Voltage, not to PWM or Auto. (Auto should work, but setting to VOLTAGE for 3-pin fans makes it sure to work.) After adjusting all headers involved, use Esc to exit back to Main Menu, then F10 to get to Exit Menu (p. 37) and SAVE and EXIT.

 

[King_V]

Thanks! I'll likely be checking it more carefully this weekend. I don't think LEDs are involved, as they wouldn't be visible with this case design. When I went to the Antec P7 Neo page, it only made mention of LED for the power switch.

And thanks for the clarification - I completely had a brain-fart moment, but now it seems obvious: if the hub is relying on external power, then, for voltage regulated fans, it's not looking at the MB header's voltage output for guidance.

 

[King_V]

Welp, not a damn thing printed on them. Just 3 fans with an Antec sticker that has a sort of sawtooth pattern printed around the edge of the diameter of the sticker.

No LED. All 3 are 120mm.

I can't imagine these draw much more than the typical amount of power.

 

[Paperdoc]

I'm sure you are right. Since there are no LED's in the fans, surely each can consume no more than 0.25 A (more likely under 0.15 A) max. Thus you could easily get s three-output SPLITTER like this

https://www.amazon.com/Cable-Matters-2-Pack-Way-Splitter/dp/B07PXLHNZ6/ref=sr_1_3?crid=2L11RXMPLKR3E&keywords=fan+splitter&qid=1646420952&sprefix=fan+splitter,aps,82&sr=8-3

That's a 2-pack of four-pin Splitters, but just use one with three 3-pin fans for your case front. Remember that the fan header can only deal with the speed signal from ONE fan, so this within this group of 3 fans on one Splitter, only ONE fan's speed will be reported to the header. The other two will be ignored completely.

Go ahead. This will work well.

 

[King_V]

@Paperdoc , well, as it is, I went with this one:

https://www.amazon.com/gp/product/B01DV1Z0Z4

Mostly out of paranoia - first, to stick to only two fans on a single header, and second, the other brand of 1->2 splitters you originally listed supposedly came out of Canada, but the company name was definitely Chinese, so that made me a bit hesitant about it.

If I do wind up putting another fan in the case, the cables of the preinstalled fans are quite long and will reach to the rear edge of the motherboard.

Definitely thanks for the tips and pointers!

 

[Paperdoc]

You're welcome and thanks for Best Solution. By the way, I sympathize on the source of things. The reality is that most of these items are made in China or other Far Eastern countries and imported into our home countries. Quality can vary widely, from very poor to excellent, and buying on-line means you can't really tell before you buy. User comments can help but are not entirely reliable, either. I DO pay attention, though, to where the item SHIPS from because that can impact delivery time a lot. Also I tend to buy from big organizations I know, like Amazon, and not from so many of their "marketing partners". If there is a problem, I have more confidence it will be addressed that way.

 

[King_V]

You're welcome and thanks for Best Solution. By the way, I sympathize on the source of things. The reality is that most of these items are made in China or other Far Eastern countries and imported into our home countries. Quality can vary widely, from very poor to excellent, and buying on-line means you can't really tell before you buy. User comments can help but are not entirely reliable, either. I DO pay attention, though, to where the item SHIPS from because that can impact delivery time a lot. Also I tend to buy from big organizations I know, like Amazon, and not from so many of their "marketing partners". If there is a problem, I have more confidence it will be addressed that way.

True, and I'm with you on that.

But with a US address, I know at least that someone's got some interest in making sure their name doesn't get tarnished.

Well, usually, anyway!