Technical rules for system fans
If there is an OCP 3.0 Ethernet adapter installed, when the system is powered off but still plugged in to AC power, fans 5 and fan 6 will continue to spin at a much lower speed. This is the system design to provide proper cooling for the OCP 3.0 Ethernet adapter.
Follow the following rules for system fan selection:
Standard fan: for processor with TDP of 155 watts or lower
- Performance fan (speed of 29000 RPM):
Processor with TDP of 180 watts or higher
Middle drive cage
Rear drive cage
PCIe SSD adapter
Ethernet adapter of 100 GbE or higher
Five system fans (fan 2 to fan 6) are adequate to provide proper cooling, if there is no M.2 drive, internal PCIe adapter, middle or rear drive cage, GPU adapter, PCIe SSD adapter, or Ethernet adapter of 10 GbE or higher on PCIe slot 7/8 installed. However, you must keep the location for fan 1 occupied by a fan filler to ensure proper airflow.