Case vs System Fan w/connector

[ltolman]

(sentence to grab attention): When buying fans; how will I know the fan has a Motherboard Connector (read on for full explanation)

Okay heres the thing: At the very present moment somehow I have a 120mm Rear Exhaust Fan for my System Fan on Motherboard. I don't know if Motherboards have multiple inputs or if its standard. But last 2 motherboards I have; it had a CPU Fan and a System Fan; nothing else.

No I haven't looked into getting some adapter thingy; moving on.

So I have my 120mm Rear Exhaust Fan for my System Fan. I needed to upgrade so I bought a replacement 120mm Fan and I needed a new Side Case Fan (if there was one)

Irony is that the new 230mm Side Case Fan I just got has a Connector to my Motherboard labeled "System Fan" I was thinking "Wow so awesome" because the 120mm replacement fan I got had nothing.

But unfortunately the 230mm Side Case Fan isn't the right size I need; I needed a step up; seeing as no 240mm exists (that I can find) I 'just bought' a 250mm

But I don't know if the 250mm Fan will actually give me a Connection to my System Fan Header for Motherboard; and if it doesn't then I need to go buy another 120mm fan that does.

What keyphrase do I need to look for when purchasing Case Fan that will allow me to connect it to the "System Fan" portion for my Motherboard?

Thanks

 

[BonzaiDuck]

(sentence to grab attention): When buying fans; how will I know the fan has a Motherboard Connector (read on for full explanation)

Okay heres the thing: At the very present moment somehow I have a 120mm Rear Exhaust Fan for my System Fan on Motherboard. I don't know if Motherboards have multiple inputs or if its standard. But last 2 motherboards I have; it had a CPU Fan and a System Fan; nothing else.

No I haven't looked into getting some adapter thingy; moving on.

So I have my 120mm Rear Exhaust Fan for my System Fan. I needed to upgrade so I bought a replacement 120mm Fan and I needed a new Side Case Fan (if there was one)

Irony is that the new 230mm Side Case Fan I just got has a Connector to my Motherboard labeled "System Fan" I was thinking "Wow so awesome" because the 120mm replacement fan I got had nothing.

But unfortunately the 230mm Side Case Fan isn't the right size I need; I needed a step up; seeing as no 240mm exists (that I can find) I 'just bought' a 250mm

But I don't know if the 250mm Fan will actually give me a Connection to my System Fan Header for Motherboard; and if it doesn't then I need to go buy another 120mm fan that does.

What keyphrase do I need to look for when purchasing Case Fan that will allow me to connect it to the "System Fan" portion for my Motherboard?

Thanks

Either "PWM" if the board has PWM fan ports, or "3-pin" -- which those same ports may also accommodate and control by voltage variation.

I suggest you make your purchases from computer-parts resellers. These fans must be 12V-DC. Take a look at the fan offerings at FrozenCPU.com and SidewinderComputers.com

And one more very important thing. Motherboards have an AMPERAGE LIMIT on what can be powered @12V from the board. Sometimes the limits are expressed as "per port;" other times as a total. Frankly, I'd limit my search to fans rated at 0.80A or less. Usually, the big 200mm fans are rated between 0.30 and 0.70A.

 

[ltolman]

deleted

 

[ltolman]

Question: Fans that have a 3pin and not a power molex.........will they achieve full potential?

I have a Titan Extreme Fan, 12v DC; 120x120x15mm it has a 3pin connector; in fact it has a Y connector allowing me to connect 2 Fans to 1 Hub; but it doesn't have a Power Molex attached to it.

Now going thru my Case and its existing fans; apparently each Fan I have has its own Power Molex connector and I have a feeling I need to keep it that way; especially my System Fan connection to Motherboard?

My Case is very old but still decent enough for I guess a mid range system? If I didn't already say:

Front Intake 120mm
Rear Exhaust 120mm
Side Case 250mm
Top Exhaust 120mm
*Bonus 90mm Fan blowing against Hard Drives*

Each of those has its own Power Molex. But soon I may have to upgrade my PC Case; I do have a Case in mind but I'm wondering if I should keep my Titan Extreme Fan that doesn't have a power molex.

Unless....because as I was trading out my Top Exhaust I saw that it had a 3pin connector and as I followed it, it was attached to a Power Molex. So maybe that's what I need? I need to buy an *accessory* a 3pin attached to a Molex? So rather than having 2 fans on 1 connection I can house it to a Power Molex?

The new case in question will have a lot more fans and I'm just not sure if I can get away with a 3pin. I did, but erased, mention that it will power up; but my computer gave me a long consistent beep (probably thinking a power problem)

Thanks

 

[BonzaiDuck]

If you want to thermally control some fans according to the temperature of the CPU or motherboard, you will want to use the 4-pin PWM and 3-pin fan ports on the motherboard. With PWM, you can connect only the signal wire to the motherboard for thermal control but power the fans directly from the PSU (Molex or SATA power-plug) -- with a $10 device like the Swiftech 8W-SPL-PWM-ST.

If you don't want to thermally control certain fans -- or any of them for that matter -- 3-pin and PWM(4-pin) converter cables are cheap and available for either Molex or SATA power connection to the PSU. Such connectors are usually bundled with any single fan purchase.

 

[ltolman]

and by "thermally control" I'm guessing me...manipulating actual fan speeds?

 

[aigomorla]

and by "thermally control" I'm guessing me...manipulating actual fan speeds?

it means there is a temp sensor on the fan itself, so as its pulling in warmer air, it automatically spins faster due to the internal resistor.

Although the concept sounds great, i have yet to see a fan with a very good one built in on such a small package.

 

[BonzaiDuck]

it means there is a temp sensor on the fan itself, so as its pulling in warmer air, it automatically spins faster due to the internal resistor.

Although the concept sounds great, i have yet to see a fan with a very good one built in on such a small package.

Not your fault, but I was referring to motherboard thermal control of fans through its ports. I had seen some of these fans in past years that had "built-in" thermal control, and didn't find them much useful for anything that I wanted to do.

More generally, and for the OP: Even cheap motherboards and processors incorporate thermal sensors for monitoring CPU and "motherboard" temperatures. Simple thermal fan control begins by using either the motherboard BIOS, proprietary mobo software, or other software to vary either the voltage on a 3-pin fan, or the duty-cycle on a PWM fan connected to the motherboard as temperature of the CPU changes.

Thus, if there is "top-end" fan-noise and you cannot muffle it by other means, you can limit or control the fan so that the noise is either less, or occurs only under extreme loading situations -- less likely during normal gameplay or regular usage.