motherboard with 8 ram slots
Asus Strix x570-f won't boot on the first two ram slot | Overclockers ...
The RAM slots are also important in a motherboard.
Make Windows 10 PC Use All RAM: Step-by-Step
If your PC isn't using all RAM, turn off Auto RAM Virtualization and check if your RAM is compatible with your motherboard.
4 RAM Slots Motherboard | Pangoly
Below is an example of the MSI Creator TRX40 motherboard that has a layout similar to most other motherboards with 8 RAM slots.