Just add another 8GB stick if you can match it

Yes, adding a second identical 8GB stick to enable dual-channel is usually the cheapest and easiest upgrade.

The performance gain from dual-channel is real — roughly 10-20% in memory-sensitive tasks — but you don’t need to buy a whole kit if you already have one stick. The trick is matching the new stick to your existing one: same speed (e.g., DDR4-3200), same timings, same voltage, preferably the same brand and model. If you can find an exact match used or new, that’s the move.

If you can’t match it or the price of a single stick is close to a kit, then just buy a 2x8GB kit and sell or repurpose your old stick. Mixing different sticks can work, but it forces both to run at the slower stick’s speed and may cause instability. Not worth the headache for a few bucks saved.

So first, check your motherboard manual and look up your current RAM model. If you can find it, buy one more. If not, go kit.

Future You will thank you for not messing with mismatched RAM.