I've got an old HP Z-620 workstation with dual E5-2697 v2 CPUs (24 cores total, 48 threads @ 2.7GHz) and 128GB of DDR3 RAM. The docs say it supports up to 192GB, but I wasn't able to get it to POST with all the RAM slots full.
It's still a "homelab" beast and does great with development and GIS/Mapping applications. I was not able to figure out how to run AI workloads on it with decent performance, however, so I finally broke down and got a dedicated GPU for it. It's pretty great what can still be done with older hardware.
I'm in the same situation of having an older workstation nearly maxed out with RAM and neither wanting to pay for the equivalent RAM on a new system neither go down in GBs.
It's still a "homelab" beast and does great with development and GIS/Mapping applications. I was not able to figure out how to run AI workloads on it with decent performance, however, so I finally broke down and got a dedicated GPU for it. It's pretty great what can still be done with older hardware.