I don't really know what that means. RAM either works, or it doesn't. While there may be faster RAM (we don't know because you didn't say what's in there now), more RAM trumps faster RAM in almost every scenario. But to that, 16GB is already a HUGE chunk of RAM and is generally considered the "sweet spot" these days. That is, less RAM and performance is noticeably degraded. But more than 16GB typically yields marginal,
at best, performance gains. In fact, more RAM may not yield any
noticeable performance gains at all. That is, except in benchmark testing, having more than 16GB often is not noticeable at all.
If I had that system, what would I do? I might replace that PSU with a nice modular "Gold" (or at least "Bronze") supply. I like EVGA and Seasonic. A modular supply will allow you to use only the cables you need. And while you will have to store separately the unused cables, it will make the interior less cluttered which promoted better air flow and cooling.
And to that, I see a single case fan in back. If none, I would look at adding at least one more in front pulling cool air in. Or perhaps one on the bottom pulling cool air in.