7 volt fan mod bad for Power supply?

[newbie1]

originally posted by NOVA5 from here (http://www.water-cooling.com/forum/viewtopic.php?t=27)

"the 7.5 volt trick is not a good idea to me. your shorting together 2 positive power leads (bad if it has nowhere to go) now granted the fan uses the power but you never know what damage ATX powersupplies will suffer from such a thing. it could be slowly killing it. a FanBus is a better and safer idea."

is this true?

volage mod i followed is here http://www.overclockershideout.com/7voltmod.shtml

[m4a2t0t]

i have heard that is not good electrical practice. all it does is use a difference of voltage potential. i dont see how it would damage the PSU.

IMO the 7 volt trick is worthless because a fan is not linear, most likely 10V will lower the noise drastically. i havent check what voltage my fans run at but im sure in in the 9-10V range and thats all i need to really quiet down a set of 131 CFM YS-tech fans

[newbie1]

i just tried it, it really did quiet down my fans, the sound of my air conditioner is finally above the sound of the fans, now my fans make more of a soothing spin, the only sound that stands out of my case is my volcano 7 HSF

my temps are about the same, a 2 degree celsius in the long run

[The Dude]

I wouldn't do it. Conventional current flow goes from + to -, +12v to ground, and +5v to Ground. If you wire it as shown +12 to +5v you reverse the current flow of the +5v power. You don't really, the current drawn by the fan actually goes to all the +5v devices connected to your Power supply and gets to ground through them. What you end up doing is increasing the current load of the +12v and reducing the load on the +5v. It probably makes it a bitch for the power supply to regulate all the voltages too.