Quietest setting for fans on AC Twin Turbo Pro?

[Morten74]

Hi guys

How do make this cooler produce the least noise? Currently I have connected the fans to the card (XFX HD5850) and fans are at 21% (lowest possible), and while it is very quiet, it is stille the 'loudest' component in my system. Would it be better to use molex-to-7v adaptor? I know that I would loose the PWM feature, but the cooler is so efficient anyway, that I would assume it would still be adequate...

Morten

[wouterr5]

You should use a PWM --> voltage converter, so that it has the full 12 volt blast when needed but can be passive in idle
But, other than this solution, there are plenty of ways to do this.
You could put a resistor in series with the 12 volt coming from the graphics card. However, this will mostly make a difference in speeds at 100% PWM and not at 20% PWM.
Using a zener diode of, say, 5 volts in series with the 12 volt from the 5850 will probably make the fan stop at lower PWM values. However, you might have trouble locating a zener diode that can handle the wattage needed.
Then there's always the option of putting it on a fan controller, a 7v supply, or the motherboard, maybe making it auto-controllable with speedfan. However, a constant 7 volt might make the fan spin faster than 21% PWM. You should try yourself to see what's quieter

[12andy]

Use MSI Afterburner to drop the fan down to 9% or so. Create a custom, less aggresive fan curve.

The fans spooling up between 9% and 20% will then drive you crazy.