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12v and 3.3v = 8.7v Fan

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Mar 7, 2002
I've seem the 7v mod applied to fans. Instead of conecting the fan ground cable to the ground pin, conect it to the 5v, and you have a 7v conection (12-5).

I'm afraid it is not reliable because I read that some fan manufacturers alerts that the fans may fail to start with voltages much below 9v. Also some people report possible PSU problems.

I'm thinking about trying conecting the fan ground to the 3.3v to have a more reliable 8.7v or in my case 9.86v as you can see below.

Did someone try it? What about the PSU problems ?
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imho, connecting it to the 3.3 isn't very smart. the 3.3 is the i/o voltage, and pumping the 12v line to it, may cause some bad instabilities. but i'm not totally sure, really there is no way of knowing what it will do until you do it. just my thoughts is that it may have not to good effects...

but it may run good, i dunno...
You mean indesirable effects like introducing fan noise in the line ?
fan noise is one factor, but another would be putting 8.7v through your 3.3 line. just think about it, the power goes from + to -, so your putting all the power from the fan to the 3.3v line would do something... especially since it is going straight to the mobo and through the board.
atleast that is how i understand it, i may be wrong, if i am, please someone correct me.