The more voltage and amps drawn through the motherboard traces create heat...And as we all know heat kills...Hook up some fan or fans that draws a bunch of amps and you take the risk of cooking the the trace...And sometimes some traces next to them.
Just a rule of thumb...Back in the day there was not much argument that connecting a bunch of fans to the motherboard was a no-no...Motherboard manufacturers started putting a bunch of fan headers without really upgrading the amout of amperage the board could handle without frying up something.
They have since upgraded the traces and the amount of amperage that the board will handle...But in my humble opinion it is still the wrong thing to do.
Just like connecting your hard drives and some of the big dog video cards that require either a floppy or molex power connector...These are definitely mission critical componets...Why have a fan that has a much higher probablity to fail and possibly take what ever else is connected to that line with it ???
On my builds I will always run all the fans from one molex line off of the power supply and make up whatever is needed to run all the fans off of it...Kind of a pain in the arse...Here is a picture of what I mean.
Fan wiring off of one molex line with fans 5 and 7 volted.
That allows me to connect everything to dedicated molex lines from the power supply for the hard drives, video card and opticals.
Yeah yeah yeah...Yadda yadda yadda...Just my two cents.
Maybe somebody else will tell you why it is perfectly acceptable to connect a fan to every possible fan header you have on the motherboard...I am just not one.
All this business is my humble opinion...Of course !!!!!
