How to Upgrade Your PC with RAM
Dual-channel: Dual-channel memory setups utilize two identical RAM modules installed in corresponding slots on the motherboard.
Which RAM Slots Should You Use? - How-To Geek
For that purpose, you’ll need to make sure that the RAM modules are placed in the correct slots. To take advantage of the dual-channel support, you have to know which RAM slots to use.
Which RAM Slot to Use? Does it Matter? - PC Guide 101
If you have a single RAM stick, it doesn’t matter which one you use first. However, with two or more sticks, the slots start to count due to Dual Channel technology.