I currently have a single 16GB Ramsta DDR4-3200 module with a heatsink. I can trade it for two 8GB DDR4-2666 modules and receive some extra cash. My CPU is a Ryzen 5 4600G. Would the performance benefit from running dual-channel memory outweigh the lower speed and reduced upgrade flexibility?
2 Answers
The trade is reasonable if you do not expect to upgrade beyond 16GB soon. Two 8GB modules let the system use dual-channel, but you lose the easy upgrade path of adding another 16GB stick later. If possible, the ideal option would be a matched 2x8GB kit rated for 3200MHz, since Ryzen APUs benefit from faster dual-channel RAM.
For a Ryzen 5 4600G, two sticks are generally the better choice because dual-channel memory noticeably improves memory bandwidth, especially for the integrated graphics. The drop from 3200 to 2666 will reduce performance somewhat, but dual-channel is usually more valuable than running one stick. Just make sure the two modules are compatible and can run together at 2666MHz or higher.

So dual-channel is better than a single 16GB stick even though the speed is lower?