Add 8GB, not 16GB.

Add the 8GB stick. It keeps dual-channel mode, which gives you better performance in everyday tasks for a lot less money.

Here’s why: With 8GB soldered, adding another 8GB gives you 16GB total running in dual-channel. That means your CPU can read from both sticks at once, which helps in games, video editing, and even just opening a lot of browser tabs. If you put a 16GB stick in the slot, you get 24GB total, but only the first 8GB of the new stick will run in dual-channel with the soldered 8GB. The remaining 8GB runs in slower single-channel mode. For most people, 16GB is plenty of capacity, so the performance hit from losing full dual-channel isn’t worth the extra capacity.

Unless you’re running huge datasets or multiple VMs that absolutely need over 16GB, the 8GB upgrade is the smarter move. It’s cheaper and faster for the stuff you do every day.