What is the correct dual channel configuration of Dell OptiPlex 5050 (Tower) motherboard

Question

I am unable to find any useful manual for this motherboard online which tells me the correct dual channel DIMMs config for this motherboard.

Can anyone suggest me the correct DIMMs config?

Answer 1

Judging from the image you posted, seems they follow the convention of the majority of motherboards (slots spaced apart are different channels, and the same colour is used for slots that should be populated at the same time), but they just coloured the retention brackets instead of the whole slot.

You should populate white slots first (DIMM 1 and 2, weird numbering), then you will have dual channel. It is good to check with CPU-Z to make sure it is working as we expected. There is no downside or risk of trying a combination.