I recently converted my old server case, motherboard RAM and CPU into a Linux workstation, that I’ve installed Kali Linux on, and will help me up-skill in computer security.
I put in a new Nvidia 710 graphics card with 2GB ram. It is entirely passively cooled and has low power usage. It is enough to do work-related stuff on my 1440p monitor. It required installed the legacy 470 graphics drivers to stop it crashing regularly, but it seems to be working fine now.
I have a 256GB SSD for the Kali install, and a 1TB storage drive for anything else (docker containers, etc).
I still have a 10Gb/sec fibre card which should run at around 4Gb/sec, allowing me to max out my 2Gb/sec internet connection.
I also chucked in an old wireless card, which I can use to try and hack my wireless network with Kali.
Everything is working well now with Kali Linux.