There's gains to be had from pushing the ram. There are good RAM overclocking guides out. What are your temps like?
This is a sub- or side-topic -- the RAM. I'm just butting in for a minute, but would make this observation.
You can buy RAM spec'd to run at DDR 4000 and beyond. I use Trident Z "GTZ" DDR4-3200 14-14-14 sticks, when I could buy faster ones. Today's RAM has more than four basic latencies to tweak, but at the same time the XMP specifications are probably optimal. You might squeeze an extra sliver or two in speed under benchmark tests, but you could also shorten the life of the modules if the tighter latencies require higher voltage, and you wouldn't much notice the difference.
That being said, the command-rate, "CR", is the simplest tweak you can make, provided you're only using two sticks in the motherboard. You can set the default command rate to 1 instead of 2. I actually believe that I can tell the difference. You might have to bump up the IMC voltage (VCCIO) a bit, or the vRAM voltage as well -- certainly. But it doesn't take a lot.
If you're using four slots, I would just buy the fastest RAM you want to use and choose the "auto" default settings for it.
Note that it's been about three years since I delved deep into the current technology of that time, so my knowledge and understanding may be stale. If I build a Comet Lake or similar computer in the next year or so, I'll have to "bone up".