Adjusting fan speed
Introduction
Starting with Dell's PowerEdge 12th generation servers, Dell has introduced a fan speed offset setting that enables fan speed to be increased and decreased. 3rd party add-in cards - such as Netscout's "Sniddely" analysis card found on TruView Packet (TVP) and TruView Appliance (TVA) - need increased fan speed to provide additional cooling.
Netscout has decided to apply a Termal Profile for maximum performance which leads to maximum fan speed and the corresponding sound level of nearly 81dBA.
Solution
 | DO NOT set the Fan Speed Offset too low. The Sniddely analysis card needs additional cooling. Setting the Fan Speed Offset too low may compromise the hardware and void warranty. As guidance, the tempertature of the CPU should never rise above 55°C |
 | Dell changed the iDRAC configuration menu ever so slightly with every new release of the firmware. The way to configure this setting may not be exactly the same as stated below. |
The Fan Speed Setting menu is found in the iDRAC Settings menu. It is not configurable via the iDRAC Web UI.
- During BIOS boot, press <F2>
- Select iDRAC Settings, then Thermal
- Click on the menu Cooling Options
The Fan Speed Offset setting allows the user to select Low Offset and High Offset.
When the Cooling Option is set to Default, the fan speed will be set to the value calculated by the Dell Themal Controller.
The Low Fan Speed Offset drives fan speeds to a moderate fan speed (approx. 50%), and the High Fan Speed Offset drives fan speeds close to full speed (approx. 90-100%).
For PCIe cards with power levels beteen 15W and 75W, it is recommended that Fan Speed Offset Low is selected. The Sniddely analysis card has a maximum power rating of 25.2W.
- Set Fan Speed Offset to "Low"
- Make sure to save the new setting when exiting system setup.
For cards expected to exceed 75W per PCIe Slot, fan speed offset of "High" is recommended.