One stick of RAM works, but you'll miss dual-channel speed.

Yes, you can install one 16GB stick now and add another later. The system will run in single-channel mode until you install the second stick. That does hurt performance for memory-intensive tasks like gaming, video editing, or heavy multitasking—usually by 5–15%, sometimes more. For web browsing, Office work, or light gaming, you probably won’t notice.

The good news: modern motherboards handle mismatched stick timing pretty well if you buy the same model later. Just make sure the new stick matches the old one in speed and capacity (ideally same kit). If you’re on a tight budget and don’t need max performance right now, one stick is a fine stopgap.

Your future self will thank you for finishing the pair.