So I finished installing a new mobo (asus p5qpl-am) for my brother-in-law. Works great and runs like a champ, no problems, but I noticed it was too loud for my taste (don't know what it sounded like before) and my brother-in-law asked me if the fan is supposed to run all of the time and why it's so loud now.

I didn't change any of the BIOS settings, in fact, didn't even go into the BIOS other than to set them as "default". Reviewing the manual I found this:

2.5.5 Hardware Monitor
CPU Temperature [xxxºC/xxxºF] or [Ignored]
MB Temperature [xxxºC/xxxºF] or [Ignored]
The onboard hardware monitor automatically detects and displays the motherboard and CPU temperatures. Select Ignored if you do not wish to display the detected temperatures.
CPU Fan Speed [xxxxRPM] or [Ignored]
The onboard hardware monitor automatically detects and displays the CPU fan speed in rotations per minute (RPM). If the fan is not connected to the motherboard, the field shows N/A. Select Ignored if you do not wish to display the detected speed.
CPU Q-Fan Control [Disabled]
Allows you to enable or disable the Q-Fan control. Configuration options: [Disabled] [Enabled]
VCORE Voltage, 3.3V Voltage, 5V Voltage, 12V Voltage [xxxV] or [Ignored]
The onboard hardware monitor automatically detects the voltage output through the onboard voltage regulators.
what is the CPU Q-Fan? (Quite?) I haven't looked yet, should this be enabled or disabled?
Is this the problem?