SC5650UP and S3420GP Full/Min Alternating Fan Speed Problem at system idle

[CARL_W_Intel]

I have a S3420GP board and SC5650 server chassis. After upgrading to the latest BIOS in order to support over 2TB hard drives, at system idle my system fans now alternate between full speed and minimum speed, with no speed variations in between. (Before the BIOS upgrade, they worked as expected based on work load). The SEL does not show any fan failures that would justify running full speed. Any guidance here would be appreciated.

[CARL_W_Intel]

Woo-Hoo, figured it out.

Server ProductsFans ramp up and down or fans boost after operating system is loadedAfter updating to the latest BIOS and loading the BIOS default values, the system may experience the following after the operating system reaches the GUI screen

1. the fans would boost to high and would stay high, or
2. the fans would boost to high and then would ramp down and repeat the scenario

To workaround this fan issue, during POST, go to BIOS by pressing -> Advanced Menu -> Processor Configuration -> Processor C6 Report -> Disabled (value would be enabled when BIOS default is loaded).Boot to the operating system and the fan issue would be resolved