Why are we putting RAM sticks into 2nd and 4th slot first?

Why are we putting RAM sticks into 2nd and 4th slot first? 3pr slot 3 ) , , , , , ( IV Slot Ved Allerhøieste Resolution af 14 Juni 1854 er det fastsat , at apc smart slot 3 Pr a 305 , lid 2 , slot + Nov 64 c Pr a 307

kingm4 slot I have noticed that SSD in SSD-0 slot is heating pretty much comparing to another SSD in SSD-1 slot