DC540’s infrastructure (remember that? physical infrastructure?) runs on two servers. We have an R620 running all the administrative crap (confluence, jira, parts db, bitbucket, etc.) and an Intel Hades Canyon NUC running all the CTF platforms.
The R620 was just upgraded to 96GB of RAM. Even cheap RAM is expensive when you buy a lot of it. I got a bunch of 4GB modules for just $6 each. This thing can handle over a terabyte of RAM, but that’s out of the financial range and kind of silly. It would be nice to get it up to 256GB, though. Unfortunately that would require 16GB modules, which are still pretty pricy, even pre-owned.
The NUC was recently upgraded from stock 32GB to 64GB, and houses two 2TB M.2 NVME sticks. It handles its business just fine.
Both are currently running on ESXi, although it has been on my bucket list to acquire another beefy Dell server, move everything off of the NUC, and rebuild it using CentOS/KVM/Qemu/libvirt. The biggest gain from this transition is that I believe it can handle inbound and outbound wifi or wired capabilities in the host operating system, making it a fully portable CTF system in a (very small) box.