Will adding 2x4GB RAM to my 2x8GB kit help reduce gaming stutter?

It may help if your games are actually using nearly all 16GB and causing paging to the storage drive. However, adding more sticks is not automatically faster. Four DIMMs can be harder for a Ryzen memory controller to run at the rated speed, so the system might need to drop below 3000MHz or use less aggressive timings. Check memory usage and frametime behavior first rather than assuming the RAM is the only cause of the stutter.

For a cleaner upgrade, I’d replace the current kit with 2x16GB DDR4 for 32GB total. A matched 3200MHz CL16 or 3600MHz CL18 kit would generally be a better long-term choice than combining two separate kits, and two sticks are usually easier to run at their rated settings on a Ryzen 5700X. The old kit can be sold or kept as a backup.

Yes, you can add 2x4GB to the existing 2x8GB, but make sure the modules are installed so both memory channels remain balanced. Also, the configuration you mean is 2x8GB plus 2x4GB; “4x2GB” technically means four 2GB sticks. Mixing kits can sometimes require lower speeds or manual BIOS settings, even when the advertised specifications match.

If 16GB is already being exhausted, 24GB could reduce the stutters, but 2x16GB gives you more headroom and avoids an awkward mixed-capacity setup. Before buying anything, confirm the committed memory in Task Manager while the games are stuttering, and also check whether the games are installed on a slow or busy drive and whether your GPU drivers are current.