James Cameron says:
Thanks for bringing this up.
A few years back I did a lot of under-voltage fan testing and came to the same conclusions as James stated.
In the end I started to select good fans and ran them at 8 volts via a 7808 regulator mounted on the inside of the case. All that's needed is the regulator chip, two small bypass caps soldered from each of the business ends to the central ground pin, and the wires from the power supply and to the fan(s). The chip can be mounted right on the case with no insulator, because the "tab" is at ground potential.
I even experimented with using adjustable regulators where I would use a potentiometer to adjust the voltage from 5 to 10.2 volts for the fans. I mounted those "pots" through a hole in the back of the case a couple of times, put knobs on them, and called them the computer "volume control". I'm sure that a better way I could have done it is with a thermostatic feedback circuit, but that's for another time.
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