If you've been eyeing off a homelab setup but the thought of a power-hungry rack server chewing through your electricity bill makes you wince, let me introduce you to what I reckon is the best kept secret in the homelab world: HP EliteDesk and ProDesk mini PCs.

These tiny desktop machines are absolute rippers for homelabbing. They're small enough to sit on a shelf, quiet enough to keep in the lounge room, and they'll cost you roughly twenty bucks a year to run 24/7. No, that's not a typo.

Why Mini PCs?

Full-size rack servers are brilliant bits of kit, but they come with baggage. They're loud — like, "why is there a jet engine in the spare room" loud. They pull hundreds of watts at idle. They generate enough heat to warm a small flat. And your partner will absolutely have opinions about all of the above.

HP's mini PC range — the EliteDesk and ProDesk in the "Mini" or "Desktop Mini" form factor — solves all of that. We're talking about a box roughly the size of a thick paperback book. No fans screaming at 3am. No noticeable bump on the power bill. And surprisingly, more than enough grunt for a proper homelab.

Recommended Models

Here's what to look for on eBay, Facebook Marketplace, or Gumtree:

  • HP EliteDesk 800 G3/G4/G5/G6 Mini — The premium line. Better build quality, more expansion options, generally the pick of the bunch.
  • HP ProDesk 400 G3/G4/G5/G6 Mini — Budget-friendly alternative. Still very capable, just slightly fewer bells and whistles.
  • HP ProDesk 600 G3/G4/G5/G6 Mini — The middle ground. Solid all-rounder.

These pop up second-hand all the time because businesses lease them for a few years then offload them in bulk. You can pick one up for $50 to $150 AUD depending on the spec and generation. Corporate cast-offs are an absolute goldmine for homelabbers.

The Money Shot: 64GB of RAM

Here's where it gets properly exciting. These little machines take up to 64GB of DDR4 SO-DIMM RAM — that's 2x 32GB sticks. Most of them ship from the office with a sad little 8GB stick rattling around in there, but crack open the bottom panel and you've got two SO-DIMM slots ready to go.

A pair of 32GB DDR4 SO-DIMM sticks will set you back about $80 to $100 AUD these days. The upgrade itself takes about two minutes — undo one screw on the bottom cover, pop it off, swap the RAM, done. That's it. You've now got a 64GB machine for under $250 all-in.

64GB is a serious amount of RAM for a homelab. That's enough to run Proxmox with a handful of VMs and still have headroom for a stack of Docker containers.

Hardware Specs

Depending on the generation you grab, here's roughly what you're looking at:

  • CPU: Intel Core i5 or i7 (6th through 10th gen depending on the G-series). The G4 and G5 models with 8th and 9th gen chips are the sweet spot for price vs performance.
  • RAM: 2x DDR4 SO-DIMM slots, up to 64GB total (2x 32GB)
  • Storage: M.2 NVMe slot (PCIe) + one 2.5" SATA bay — dual storage out of the box
  • Graphics: Intel UHD integrated graphics (plenty for a headless server)
  • Network: Gigabit Ethernet (Intel NIC on most models)
  • Ports: USB 3.0, USB-C (on newer models), DisplayPort, audio jack
  • Size: Roughly 177 x 175 x 34mm — genuinely tiny

Power Consumption: The $20/Year Maths

This is the bit that makes these machines so attractive for always-on homelab duty. At idle, an EliteDesk Mini pulls somewhere between 8 to 15 watts. Under moderate load — say, running a few VMs and some Docker containers — you're looking at 30 to 35 watts tops.

Let's do the sums for a typical setup sitting at around 15W average draw:

15W x 24 hours x 365 days = 131.4 kWh per year

At roughly $0.15/kWh (typical Aussie rate):
131.4 kWh x $0.15 = $19.71 per year

Call it twenty bucks a year. Your electricity rate might be a bit higher or lower depending on where you are and what plan you're on, but we're talking pocket change either way. Compare that to a second-hand Dell PowerEdge pulling 150-200W at idle — that's ten times the running cost before you've even done anything useful with it.

Tip: If you want to check your actual power draw, grab a plug-in power meter from Bunnings for about $20. Handy for measuring any appliance, not just your server.

What to Look for When Buying

Not all of these machines are created equal. Here's what to check before you hand over your cash:

  • CPU generation: 8th gen (Coffee Lake) or newer is preferred. You get better virtualisation support (more VT-x/VT-d features), improved performance per watt, and better iGPU for any transcoding work. The G4 models and up generally have 8th gen+.
  • SO-DIMM slots: Make sure the model has two SO-DIMM slots. A few of the ultra-budget ProDesk 400 variants only have one slot, which caps you at 32GB. Two slots is what you want.
  • NVMe support: The G3 models have M.2 but some only support SATA M.2, not NVMe. G4 and newer generally support NVMe without dramas. Check the spec sheet for your exact model if you're buying a G3.
  • Condition: These are ex-corporate machines, so expect some cosmetic wear. That's fine — you're not entering it in a beauty contest. Just make sure it POSTs and the ports all work.
  • Power adapter: Make sure it comes with one. Replacements are easy enough to find, but it's one less thing to sort out.

RAM Upgrade

Upgrading the RAM is dead simple:

  1. Buy 2x 32GB DDR4 SO-DIMM sticks (2666MHz or 3200MHz depending on what the board supports — check your model). These are about $80-100 AUD for a pair.
  2. Flip the machine over, undo the single screw holding the bottom cover.
  3. Slide the cover off.
  4. Pop out the old RAM sticks (push the metal clips on each side outward).
  5. Slot in the new sticks at a 30-degree angle, then push down until they click.
  6. Put the cover back on, do up the screw, boot it up.

Seriously, it takes two minutes. HP made these things easy to service because they were designed for corporate IT teams who needed to deploy hundreds of them.

Storage Upgrade

While you've got the cover off, you might as well sort out storage too:

  • NVMe SSD (M.2): Grab a 500GB or 1TB NVMe drive for your OS and VM storage. Fast reads and writes make a massive difference for virtualisation. A decent 1TB NVMe is around $80-120 AUD.
  • 2.5" SATA: Use the SATA bay for bulk storage — media files, backups, whatever you need. A 1TB or 2TB 2.5" SATA SSD or even a spinning disk works fine here.

Two storage devices in a box this small is genuinely impressive. NVMe for speed, SATA for capacity — sorted.

What Can You Actually Run on It?

With 64GB of RAM and a decent i5 or i7, you'd be surprised how much you can cram onto one of these:

  • Proxmox VE — Full virtualisation platform. Run multiple VMs and containers side by side.
  • Docker containers — Dozens of them. Media servers, dashboards, monitoring, reverse proxies, the lot.
  • Virtual machines — A couple of Linux VMs, a Windows VM for testing, maybe a pfSense/OPNsense firewall VM.
  • NAS — Run TrueNAS or OpenMediaVault in a VM with the SATA drive passed through for file sharing.
  • Media server — Plex or Jellyfin with hardware transcoding via Intel Quick Sync (the iGPU handles this surprisingly well).
  • Pi-hole / AdGuard Home — Network-wide ad blocking.
  • Home Assistant — Smart home automation.
  • Anything else — Gitea, Nextcloud, Vaultwarden, game servers, monitoring stacks — go nuts.

Mini PC vs Full Rack Server

Let's be real about the trade-offs:

  • Performance: A rack server with dual Xeons will absolutely smoke a mini PC in raw compute. But for a homelab where you're learning, tinkering, and running services for yourself and maybe your household — the mini PC is more than enough.
  • Expandability: You're limited to 64GB RAM, one NVMe, and one SATA drive. No PCIe slots for a 10GbE card or HBA. If you need serious storage or networking, a rack server wins.
  • Noise: The mini PC wins by a country mile. It's basically silent. You can keep it in your bedroom and sleep fine.
  • Power: 15W vs 150W+ at idle. Over a year, that's the difference between $20 and $200+. Over five years, you've saved a grand.
  • Space: Fits on a shelf, in a drawer, velcro'd to the back of a monitor. Try that with an R720.
  • Partner approval factor: High. Very high. No one's going to complain about a silent box the size of a sandwich.
Pro tip: If you outgrow one mini PC, just buy another one. Two EliteDesks with 64GB each still use less power than one rack server, and you get the added bonus of redundancy. Cluster them with Proxmox and you've got live migration between nodes.

The Bottom Line

For somewhere around $200-250 all-in (machine + RAM + storage), you get a capable, quiet, power-sipping homelab server that'll happily run 24/7 for years. Twenty bucks a year in electricity. No noise complaints. No heat issues. No regrets.

If you're just getting started with homelabbing, or you want a low-power always-on server for Docker and a few VMs, an HP EliteDesk or ProDesk Mini with 64GB of RAM is genuinely hard to beat. Get on eBay, grab one, chuck some RAM in it, and you're laughing.