Overclocking on the Z590 platform is pretty much the same as what we saw on Z490. You will notice, at least with the Core i9-11900K that you are not going to be able to get a whole lot more out of these chips. I decided to do all of my overclocking using the Intel Extreme Tuning Utility. Opening it up by default in Advanced Tuning we can see the break-down of ratios by active cores.
To set an all-core overclock all we have to do is adjust these values. After much testing we were able to achieve a stable overclock of 5.0 GHz (50x) with a set Vcore of 1.37V.
Running the CPU stress test it passed, but our temperatures decently high, so that is something you might want to keep an eye on.