Well, I guess I can announce my new build project (The eBay Home Supercomputer) by showing off one of the stars: one of two AMD EPYC 7B12 processors. Retired from the Google Cloud Platform, this chip has 64 cores (128 threads), 256MB of L3 cache, and runs at 2.25GHz base, 3.3GHz boost, putting its specs close to the public EPYC 7742 processor.
The major parts were obtained on eBay, the case from Newegg. This is going to be a fun build.