Whatever amperage you draw on the 7 volt trick, must also have a return path to ground: the PSUs +5 volt line does not accept reverse current: the PSU will automatically shut down.
In other words, you must have something, anything connected to the +5 line that draws at least the same current.
Other than than, you may be introducing some transients from the +12 line, onto the +5 live. A +12v line is spec'ed with max 100 mV voltage ripple. The +5V line is spec'ed with max 50 mv voltage ripple. Probably nothing to worry about, but something that you might want to keep in mind, if you're a serious overclocker.
|