I've recently built an i7-920 system around an Asus P6T motherboard, Noctua NH-U12P CPU cooler, Antec 300 chassis (built in rear and top fans) and Enermax UC-12EB front chassis fans. It runs Vista 64-bit, and everything works great EXCEPT one thing:
First, the Noctua CPU cooler comes with two NF-P12 3-pin fans. I've got one plugged into the motherboard CPU Fan connector (there's only one), the other into one of the motherboard's Chassis fan connectors. One of the Enermax chassis fans is plugged into the remaining motherboard Chassis fan connector.
Trouble is, *none* of the speed control seems to really work. The 3-pin CPU fan runs at 100% speed regardless of either BIOS or SpeedFan or Asus speed control software setting. All see the RPM just fine, but no control. Contacting Asus confirmed that the 4-pin motherboard connector only supports 4-pin fans. There is no way to set the BIOS to control a 3-pin fan. (You wouldn't know this from the wording on the Noctua website, for what that's worth).
However, the motherboard's chassis fan connectors are both 3-pin and are supposed to be controllable too. I wish that were true. Neither the 2nd Noctua fan, or the Enermax fans can really be controlled. I can turn them on(anything >0%) or off (0%), but regardless of percent setting, the fans both operate at the same speed. I've observed this behavior via BIOS, SpeedFan, and Asus speed control software settings.
Has anyone else observed this problem? Is there some kind of "secret" BIOS setting that I'm missing? (I've enabled and disabled speed control in BIOS and results seem same). Do some kinds of fans just resist being speed controlled and I just picked the wrong ones?
First, the Noctua CPU cooler comes with two NF-P12 3-pin fans. I've got one plugged into the motherboard CPU Fan connector (there's only one), the other into one of the motherboard's Chassis fan connectors. One of the Enermax chassis fans is plugged into the remaining motherboard Chassis fan connector.
Trouble is, *none* of the speed control seems to really work. The 3-pin CPU fan runs at 100% speed regardless of either BIOS or SpeedFan or Asus speed control software setting. All see the RPM just fine, but no control. Contacting Asus confirmed that the 4-pin motherboard connector only supports 4-pin fans. There is no way to set the BIOS to control a 3-pin fan. (You wouldn't know this from the wording on the Noctua website, for what that's worth).
However, the motherboard's chassis fan connectors are both 3-pin and are supposed to be controllable too. I wish that were true. Neither the 2nd Noctua fan, or the Enermax fans can really be controlled. I can turn them on(anything >0%) or off (0%), but regardless of percent setting, the fans both operate at the same speed. I've observed this behavior via BIOS, SpeedFan, and Asus speed control software settings.
Has anyone else observed this problem? Is there some kind of "secret" BIOS setting that I'm missing? (I've enabled and disabled speed control in BIOS and results seem same). Do some kinds of fans just resist being speed controlled and I just picked the wrong ones?