Dual-channel memory will dramatically improve your 5600G's gaming performance.

Yes. Adding a second 8GB stick to run dual-channel will be the single biggest performance upgrade you can make to that system short of buying a dedicated GPU.

Your integrated graphics (the “G” in 5600G) has no dedicated VRAM — it uses system RAM. With single-channel, you’re choking the iGPU’s memory bandwidth to roughly half its potential. In many games, this can mean 30-50% higher frame rates just by going dual-channel. It’s not subtle.

The 5600G’s Vega 7 iGPU is actually pretty capable for 1080p low/medium gaming, but it’s entirely bandwidth-limited. Single-channel memory is like giving a sports car bicycle tires. You’ll see stuttering, lower minimum FPS, and worse 1% lows even in lighter games.

So yes, go buy that second stick. Ideally get the exact same model for compatibility, but any DDR4-3200 CL16 stick will work. Future You will thank you.