Motherboard fan connectors typically use a small
3-pin which looks like this:
the left connector is a female connection (the side with 3 holes) the middle and right are male connections, has 3 metal pins:
- Black: GND (ground)
- Red: +12VDC or +5VDC (12V or 5V DC - direct current)
- Yellow: Tachometer signal (used to read fan speeds)
Wire color may vary, and some fans or motherboards may control fan-speed.
Some fans use a 4-pin connection, which is generally a CPU fan connector but not always:
This pictures a 4-pin connection, but may look different from other 4-pin connections because the wires are covered in a black sleeve, which keeps them safe from harm and to reduce potential negative affects on airflow created when there are lots of loose wires inside a computer case.
This photo shows a 4-pin connection attached to a motherboard next to a 3-pin connection in a motherboard. While it is not recommended in the case of the CPU's fan, in the case of other internal case fans with a 4-pin connection, it is possible to plug them into a 3-pin connector of the motherboard, but the ability to control fan speed, which is controlled in the 4th pin will be lost.
Though sometimes computers have a way of controlling fan speed on a 3-pin or 4-pin connection even without the 4th pin, such *** voltage regulation and reading tach. feedback. These things are typically things a general user doesn't need to worry about unless their computer is running particularly hot and causing trouble.
In which case, it might be worth investing some money in a fan controller, which takes a power connection, several fan connections (varies based on the controller you get) and gives you the ability to control fan speed externally on your computer case. My controller has nice dial knobs, though some "fancy" controllers have a display and up and down buttons. (Fan controllers would be at your own discretion in terms of price, you can get them cheap all the way up to seemingly ridiculous expensive)
In the event of not having enough 3pin or 4pin connections on a motherboard, it is still possible to add case fans by way of 4pin molex connections:
A female molex connection
A male molex connection
Some case fans run exclusively through these connectors, others have a combination of a 3pin (or 4pin possibly, though I've never seen this combination) and a 4pin molex connector. In this case, the molex connector can connect directly to a cord from the power supply and run the fan. It is possible to run case fans without having them connect to the motherboard at all! Which makes it possible to connect more fans, with less available connections for your fans on your motherboard.
If a fan is a certain connection (any of the 3) and you need to convert it, for example:
- a 3pin to a 4pin molex because your motherboard doesn't have enough 3pin connectors for all your fans,
adapters are available to change one type of connection to another, at many online retailers (such as newegg.com, amazon.com, or other electronic supply retailers) and some retail stores, Best buy might
have something, though you'd have a safer bet at a store like Micro Center which is more specialized for PC building or an alternative PC/electronic store.
To ensure you solve your problem, just be sure to familiarize yourself with the motherboard you are planning on buying (or have) and the fans you plan to have inside your computer. It can be a bit more work to check the specs on the fans and motherboards, but a little work saves hours of headache later.