max safe wattage for a mobo fan header?

[Bulk Beef]

I have a 3.0 watt fan that I'd like to power off the motherboard, but I don't want to zap the board.

Anybody know this? I searched and found nothing.

 

[Boonesmi]

if memory serves most motherboards are supposed to support up to 4w per header.... but that seems pretty high to me i would be hesitant to use anything over 3w

as a side note if you do use to powerful of a fan it usually only burns out that header, but rest of the board usually still works fine

 

[mechBgon]

Check your motherboard manual and see if they specify. If not, I'd be conservative and recommend 2.5W or less per header (and I've blown a couple before ).

 

[SmokkinJoe]

3 watts is a lot for a mobo header, after doing some testing on my own system I have found that for stability it is best to keep all fans off of mobo headers and just use the 4 to 3 pin adapters. Depending on how big your power supply is and how many fans you already have it can become a big performance and stability issue.

Joe