4-pin Fan Connectors

[SlipperyPete]

Hey everyone. Back in the S939 days people would say not to plug any fans into the motherboard for optimum OCing ability. Now it seems a lot of folks are using the new 4-pin fan headers to allow the computer to self-manage the fans so they speed up when needed automatically. This is a great idea and something I would want to do.

Is it still true that plugging fans into the motherboard will interfere with the CPU's power and affect OCing ability?

How can I plug 3-pin plugs into 4-pin headers and still have the ability to allow software to manage fan speed? I am using Panaflo and Vantec fans...

 

[paul-e-wog]

Sorry, but I don't think any software has that capability currently. The fourth wire is necessary for software speed control.

Have you considered purchasing a 'dumb' hardware speed control? Or perhaps you may be interested in purchasing fans that automatically regulate their own speed via a temperature sensor wired to the fan.

 

[BillParrish]

Is it still true that plugging fans into the motherboard will interfere with the CPU's power and affect OCing ability?

I do not think it was ever true. And if it ever was, that was some very crappy motherboard or power supply. The motherboard in your sig, it is not a concern. Hooking up to 1.5A (18W of fan to each header) is fine although I would limit it to 1A (12w) just to avoid any chance of blowing out the fan power circuitry.

It all depends on the fan controls in the bios and the headers on the motherboard.
Most motherboards only the header for the CPU fan is 4 pin pwm speed controlled. In most but not all bios you can set the "mode" of that header, pwn for 4 pin temp speed control using pwm, legacy for voltage control of a 3 pin fan where the temp sensor on the board in the cpu socket well is used to vary the voltage fed to the 3 pin fan and vary its speed. Off, which will run either a 3 or 4 pin fan full speed and AUTO where the header will try to figure it out based on the fan used.
(actual labels in the bios will differ between brands of boards, some or all features or even more options may be present)

Now on to the other fan headers, 95% of boards will just have 3 pin headers for the system and aux fans. If there is another 4 pin header it may or may not have individual settings like the cpu fan. Most boards just have the extra 4 pin header set up to do whatever you set for the cpu fan header.

Manual - Page 26 and page 60.

What is interesting is they do not say how the SYS_Fan2 which is also a 4 pin pwm fan header is controlled. There are two possibilities, it is the same as the cpu fan, or if they did a good design job it adjusts fan speed by the second on board thermistor located near theMCH/Northbridge PCI slots that monitors "MCH" temp. Or something completely different. You could ask Gigabyte tech support if no one here knows for sure.

How can I plug 3-pin plugs into 4-pin headers and still have the ability to allow software to manage fan speed? I am using Panaflo and Vantec fans...

Paul is correct, you cant. Fans will run at 100% when plugged into a 4 pin header (this is fine and will not hurt the fan or the motherboard)

Easytune which is Gigabytes Windows based tweaking software is about your only chance. Fire it up and see what it has for fan speed options over and above the fairly limited ones in the bios.

I am fairly certain the 3 pin headers do not have the ablity to do any voltage control so speedfan will not work to adjust their speed automatically. The Easy Tune would be the clue, if you can adjust the speed of the 3 pin fan headers in Easy Tune you should also be able to configure them with Speedfan but again, pretty sure thats a no-go.