Not every spare PC can become a Proxmox host, and the specifications that decide it are not the ones on the shop sticker. Hardware virtualisation support is non-negotiable, and RAM — not CPU speed — is the budget every VM will spend. Here is the honest checklist to run before you install anything.
The Proxmox installer will happily start on the wrong machine and waste your afternoon. Ten minutes of checking first tells you whether a PC will be a pleasant little server or a slow disappointment. Two facts decide almost everything: does the CPU do hardware virtualisation, and how much RAM is really in the box?
Every virtual machine Proxmox runs is a KVM machine, and KVM is hardware virtualisation. Your CPU must support Intel VT-x or AMD-V, and the feature must be enabled in the BIOS/UEFI — on many office PCs it ships switched off. If the setting is missing entirely, the CPU is simply too old, and no setting, driver or trick changes that. Be honest about this check before you move a single cable: find the CPU model, confirm it on the manufacturer's specification page, then enter the BIOS and look under Advanced or CPU Configuration for Intel Virtualization Technology, VMX, SVM Mode or AMD-V and switch it on.
Sellers advertise cores; Proxmox hosts run out of RAM. Every running VM keeps its assigned memory, and the host needs roughly 2 GB for itself. The maths is unforgiving:
You can technically assign more RAM than the machine has ('ballooning' and overcommit exist), but the day two VMs both actually use what they were promised, the host starts swapping to disk and everything slows to a crawl. Plan with real numbers. A cheap second-hand RAM upgrade is the single best money you can spend on a Proxmox box.
CPU: almost any 64-bit Intel Core i5/i7 or AMD Ryzen from the last decade is plenty for a home or small-office host. Cores get shared and mostly sit idle; you only feel CPU limits when several VMs work hard at the same moment. Disk: an SSD for the system and VM disks makes a bigger difference than two extra cores — VMs on a spinning hard disk feel old even on a fast CPU. Keep a second disk or a NAS in mind for backups from day one. Network: one ordinary gigabit port serves a home lab fine. Two ports only matter when you start separating networks or building clusters — not day-one concerns.
The ideal candidate is boring: a mid-age office desktop with a VT-x/AMD-V CPU, 16 GB or more of RAM (or empty slots to reach it), and an SSD — or space to add one. The poor candidates are equally clear: a pre-VT-x museum piece, a laptop with 4 GB soldered RAM (it will work as a toy and frustrate as a server), and — this one matters — the only PC your household or office actually depends on. Proxmox takes the whole machine and the whole disk. Pick the PC nobody will miss for a weekend while you learn.
See the full Proxmox installation and first VM creation, live and step by step.
▶️ Watch Full VideoFind the exact CPU model in your current system settings or on the machine's specification page, then look it up on the manufacturer's site — Intel and AMD both list virtualisation support per model. The practical test is the BIOS itself: if a setting like Intel Virtualization Technology or SVM Mode exists and can be enabled, you are good.
Yes, within honest limits: the host takes roughly 2 GB, leaving about 6 GB for guests. That runs one small Linux VM and a few light containers comfortably. It will not run a Windows VM alongside several other machines without swapping and slowing everything down.
For learning, yes — many people start there. As a 24×7 server it has real weaknesses: limited RAM, one disk, a battery that becomes a tiny built-in UPS but also a heat and wear problem, and it sleeps or throttles in ways desktops do not. Fine for a lab, poor as the office's only server.