View Full Version : Running 3 San Ace fans using 7V trick
silverphoenix
08-06-2008, 08:20 PM
Will running 3 San ace fans using the 12V-5V trick be to unhealthy for my PSU?
Big_Daddy
08-06-2008, 08:21 PM
Depends on the PSU, if it's a multi rail, try splitting them up. Also, don't try using the RPM sensor, it will freak your mb out.
silverphoenix
08-06-2008, 08:25 PM
PSU is the Corsair 620HX pretty beefy, but I dun wanna do anything detrimental to it.
-edit looked up the specs, the 5V line can handle up to 3A, now 3 San's will be drawing somewhere around .4-.55A at 7V is my guess. I'm not sure how many more components use up the 5V line. I'm not to crazy about big adjustable knobs I just need the fans to switch from 7-12V and one switch in the back or something is perfect.
Big_Daddy
08-06-2008, 08:29 PM
It's not the current, its the ground. It should be fine, just remember the RPM. Some fans go funny when you do the 7v trick and the RPM sensor takes the brunt. If the RPM doesn't work, don't tie the ground into it. (remember, your 5v is now your ground)
Some fan RPM sensors need to have the ground AND the rpm sensor, you cannot do that in this case.
silverphoenix
08-06-2008, 08:32 PM
I know I can run the san ace using this trick no problems I've done it before but in an external WC box with it's own dedicated PSU.
Point is not that the 5v line can handle 3A, since u will be feeding into the 5v line. The rest of the machine have to pull more from the 5v than the fans are feeding into it. If the machine do it will be fine, if it dont.... well i dont actually know what can happend.
He's got 4 hard drives, those have to create a half-decent draw on the 5V line.
71 (Bryan)
08-07-2008, 05:43 AM
i would use one of those small vario resistor that they use for vmods and hide them somewhere none can see ans use that to control the fans (on hte 12 volt line ofcourse)
Sparky
08-07-2008, 05:45 AM
Um the 5V rail can handle a lot more than 3A. 3A is practically nothing.
silverphoenix
08-07-2008, 05:46 AM
Um the 5V rail can handle a lot more than 3A. 3A is practically nothing.
I read wrong lol 3A is for the 5V sb
the normal 3V rail can handle up to 30A.
MadHacker
08-08-2008, 05:40 AM
I do that all the time (7v trick) works very well.
I also have a 620HX but have been doing it for years on various power supplies without any problems
WhiteFireDragon
08-08-2008, 06:27 AM
what exactly is the 7v trick? and since we're on the same subject, which wires on the molex connector are used when running the 5v line?
tw33ter
08-08-2008, 06:46 AM
Here ya go...
http://img139.imageshack.us/img139/2456/psplugvb9.gif
http://img181.imageshack.us/img181/2077/28424761tw3.gif