This is by design. There is no memory controller Gear 1 or Gear 2 option in the Dell OEM (original equipment manufacturer) BIOS. The retail Intel documentation discussing memory controller Gear 1 and Gear 2 do not apply to the Dell OEM BIOS, motherboard, and ram.
Dear Dell Team, dear community, some technical findings with your latest Aurora R12 Rocket Lake rigs with a focus on memory. [IMAGE]   Issues:1) Memory Controller is fixed to Gear 2 Mode despite memory clock. It should stick to Gear 1 until 3600MT/s memory frequency. Otherwise an option in BIOS has to be provided to change modes manually. 2) Read Value has a consistent and massive penalty applied when any XMP profile is enabled. 3) Memory latency is too high for the trained values. Please compare with Gigabyte, ASRock, MSI, ASUS motherboards with same kit and CPU. 4) CPU cache is all over the place with massive fluctuations that will impact gaming likewise (esp. L3). It is reasonable to continue using Z490 for Rocket Lake. The choice not to allow for manual memory overclocking is fine IF the above is fixed given you are marketing the product to a certain clientele. Yet the necessary work to at least deliver an acceptable performance in line with other board manufacturers has to be done. Unfortunately, in the current state, this system configuration is unacceptable. Please check with the ODM of the board and make necessary adjustments. Should you have any further questions please do not hesitate to contact me.
Aurora R12, Unacceptable BIOS/Z490 configuration, 11th Gen Intel CPU's 
(RocketLake)