MB Fan Power Limitations

I want to start connecting all my fans to the motherboard (im building my computer atm) but there are opt_fan and cha_fan. What is the differences exactly? One uses temperature sensors in the motherboard and adjusts the fan speed accordingly and the opt fan uses the temperature sensor that you install next to the opt fan port and adjusts it according to that? What if i connected it to the opt fan port without connecting the temperature sensor?

My question is, I have three 230mm fans and one 140mm fan in my case and I want to use them all but I'm not sure if the 230mm fans take too much power for it to be safe for the motherboard.

The 230mm fans take .4A (I had to look it up) and im sure the 140mm should probably be fine connected to the motherboard since it will probably take much less power.

The manual says "The fan connectors support cooling fans of 350mA-2000 mA (24W max) or a total of 1 A-7 A (84W max) at +12V."

But can someone explain that more clearly? I believe .4A converts to 400mA so it should be well within the range of what the manual said or do I run the risk of frying the fan connectors? I really dont want to blow the fan ports so I need to make sure the 230mm fans arent pulling too much amps to damage them. If it's much safer, I can connect them direct to the power supply but then they would run full speed all the time. I dont know if its even possible but would it somehow be possible to make the fan run off the power from the power supply but have the motherboard regulate how fast the fan goes?

Thank you for your help!
4 answers Last reply
More about power limitations
  1. Your fans shouldn't overload the board, but they may still run at full speed off the motherboard. If your board bios has smartfan, this feature may only control the cpu fan. You'll just have to try it.
  2. The board can deliver all the power you need to run the fans at full speed. Whether you can control the fan speed of all of them depends on your board. If you have an overclockers type motherboard, you can mostly control all of them from the bios. However most mainstream mobo's don't have that option. In that case you'll need a hardware fancontroller
  3. Thank you for your help. I do have a fan controller with my motherboard so I should be okay.
  4. You're welcome!
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