Max fan amperage for motherboard.

[valebornemann]

I want to connect a high-ampere fan to an ASRock fatal1ty h87 performance.
I just have to know wether to get a 0.2A, 0.5A or 3.9A fan (the higher, the better).
(I want to buy a Delta fan, btw.)
Any ideas?

 

[Eximo]

They don't specify it, best to ask ASRock.

 

[mortemas]

No way the 3.9A fan will be supported. You could get a fan hub that uses 12v directly from the PSU. It responds to the sense cable of a master fan plugged into a specific port on the hub. All other fans on the hub will speed up and slow down with the master. This one is a PWM hub: https://www.silverstonetek.com/product.php?area=en&pid=526

So, even if you only connect 1 fan to it, the fan power is not coming from thru the mobo. Still, 3.9A is a lot. What's the exact model number of that fan? That's a nearly 50W fan, so you'll have to watch your power budget on your PSU's 12v rail. And the controller above might not even work with it.

 

[geofelt]

As I recall, 1a is a common limit for a motherboard fan header.
But, verification is best if you are going to go past that.

Might I ask exactly what the situation is, and why you might need such a high rpm fan that needs motherboard control?

 

[valebornemann]

I read on another thread that the amp support is probably ~1A on this kind of motherboard fan port.
These two fans have less than <0.55A each:
https://www.newegg.com/Product/Product.aspx?Item=N82E16835213005&cm_re=delta-_-35-213-005-_-Product
https://www.newegg.com/Product/Product.aspx?Item=9SIAGGG7SN6034&cm_re=delta-_-35-706-036-_-Product
Would you say that they would be sufficient with ~120 CFM and ~10 mmH2O?

 

[valebornemann]

As I recall, 1a is a common limit for a motherboard fan header.
But, verification is best if you are going to go past that.

Might I ask exactly what the situation is, and why you might need such a high rpm fan that needs motherboard control?

Its for a small PC that runs hot for very long, in a case with 2*120mm fan slots.
Noise isn't a problem and so isn't power-usage.

 

[mortemas]

Ok, so that’s a 3-pin fan and current draw is 0.46A. It’s rated at 0.70A peak, which is probably at startup. If you’re comfy with those numbers and your mobo supports 3-pin fans then give it a try. If you want to be more cautious, power them with a hub or get a molex to 3-pin adapter and run them directly from the psu at full speed or add a speed controller if you want to slow them down a bit. Is this a mission critical computer?

 

[valebornemann]

Ok, so that’s a 3-pin fan and current draw is 0.46A. It’s rated at 0.70A peak, which is probably at startup. If you’re comfy with those numbers and your mobo supports 3-pin fans then give it a try. If you want to be more cautious, power them with a hub or get a molex to 3-pin adapter and run them directly from the psu at full speed or add a speed controller if you want to slow them down a bit. Is this a mission critical computer?

It will be, if it works.

 

[mortemas]

OK, so no risk of interrupting existing processes, but risk of delaying startup of your intended endeavor if you overload the fan header(s) and damage the mobo. Personally, I would go the way of peace of mind and use a hub to power the fans. You're talking maybe an extra $20 versus delays and $$$ to replace a mobo if it's damaged beyond repair. Now, the damage could be limited to just the fan header if a component within the fan circuit fails, but with multilayer circuit boards a burnt trace can take out neighboring circuits. Is 1.4A going to burn up your mobo? We simply don't know if the mobo manufacturer doesn't specify, but the most common fans don't really use more than 0.13 to 0.15 A and unless it's a high performance board designed for overclocking I would assume the mobo was designed for average fans. Bear in mind that you need to know if your mobo supports 3-pin or 4-pin fans. The hub I linked to above is for 4 pin fans. Here's a hub for 3-pin fans with a knob for speed adjustment and they were even kind enough to specify max current capability of 3A for the device: https://www.newegg.com/Product/Product.aspx?Item=9SIACJF6WW4378&cm_re=3_pin_fan_hub-_-9SIACJF6WW4378-_-Product

 

[mortemas]

Ha! Just reread your original post and your mobo literally has "Performance" in the name. At 0.46A each, it might be ok to just plug the two fans into the mobo.

 

[valebornemann]

OK, so no risk of interrupting existing processes, but risk of delaying startup of your intended endeavor if you overload the fan header(s) and damage the mobo. Personally, I would go the way of peace of mind and use a hub to power the fans. You're talking maybe an extra $20 versus delays and $$$ to replace a mobo if it's damaged beyond repair. Now, the damage could be limited to just the fan header if a component within the fan circuit fails, but with multilayer circuit boards a burnt trace can take out neighboring circuits. Is 1.4A going to burn up your mobo? We simply don't know if the mobo manufacturer doesn't specify, but the most common fans don't really use more than 0.13 to 0.15 A and unless it's a high performance board designed for overclocking I would assume the mobo was designed for average fans. Bear in mind that you need to know if your mobo supports 3-pin or 4-pin fans. The hub I linked to above is for 4 pin fans. Here's a hub for 3-pin fans with a knob for speed adjustment and they were even kind enough to specify max current capability of 3A for the device: https://www.newegg.com/Product/Product.aspx?Item=9SIACJF6WW4378&cm_re=3_pin_fan_hub-_-9SIACJF6WW4378-_-Product

the MOBO supports 3 and 4 pin.