BTW, I have one mystery to track down. On my older MSI board, I was able to achieve more than the Intel-advertised Max Turbo Frequency of the i7-7700K by just turning on the Game Boost feature.
i7-7700K
Base clock: 4.2 GHz
Max Trubo: 4.5 GHz
Game Boost Enabled: 4.8 GHz
However ..
i7-9700K
Base clock: 3.6 GHz
Max Trubo: 4.9 GHz
Game Boost Enabled: 4.7 GHz
I think the Game Boost should at least give the CPU setting for the Intel Max, or another 0.2 GHz. I was expecting 5.0 off the bat, with MAYBE 4.9 as a minimum boost.
I know the new CPU is much faster than the old one. But, there are those who see very stable settings running the 9700K at 5.0 GHz.
More fun!! 
What Operating system do you plan on running on your server?
I have a server too, but its a prebuilt Dell server with Xenon CPU, 64gb ECC RAM, etc.
Its a VM server, running VMWare's ESXi. If you just install ESXi the software is free to use but is neutered (doesnt allow vMotion, Host Clustering, etc, etc) vs the paid vSphere license.
My main VM that I run is Windows 2016 Server that hosts my Plex Server. I also run a couple of other VMs: pfSense firewall VM, Windows 10 VM that hosts my thin client image, Ubuntu VM, Kali Linux VM, and a bunch of other VMs that i run every now and then. I have all of these VM's cause i work in IT and use it as a lab to practice/learn new configurations and such. Plus im just a nerd and its fun to me.
I may actually build another server with an i7 or i9 CPU and dedicated GPU and put Windows 2019 Server on it as the hypervisor and run Hyper-V. Hyper-V allows you to passthru the GPU the VM's, so basically you can game on the VM. If I do go through with this build and QoS is good enough with the gaming, I may just get rid of my dedicated gaming PC and just run all my games off the VM hosted on the Hyper-V server, and have my thin client on my desk to connect to the VM.