So you've picked up a cheap HP EliteDesk or ProDesk mini PC and you're ready to turn it into a proper homelab machine. The single most impactful upgrade you can do is maxing out the RAM. Good news — it's one of the easiest hardware upgrades you'll ever do. We're talking one screw, two minutes, zero stress.

What RAM Do You Need?

HP EliteDesk and ProDesk Mini PCs use DDR4 SO-DIMM memory — that's the laptop-sized stick, not the full-length desktop DIMM. Most models have two SO-DIMM slots, which means you can fit up to 64GB (2x 32GB sticks).

Here's what to buy based on your model generation:

  • G3 models (6th/7th gen Intel): DDR4-2400 SO-DIMM. Max 64GB on most models, though HP's official spec sometimes says 32GB — ignore that, 64GB works fine.
  • G4 models (8th gen Intel): DDR4-2666 SO-DIMM. Max 64GB.
  • G5 models (9th gen Intel): DDR4-2666 SO-DIMM. Max 64GB.
  • G6 models (10th gen Intel): DDR4-3200 SO-DIMM. Max 64GB.
Important: Always use matching pairs — same brand, same size, same speed. Mixing and matching different sticks can cause instability or boot failures. Buy a kit of two if you can.

How Much RAM Do You Actually Need?

Depends what you're planning to do with the machine:

  • 16GB (2x 8GB): Fine for basic Docker containers — Pi-hole, a reverse proxy, a few lightweight services. You'll run out pretty quick if you start spinning up VMs though.
  • 32GB (2x 16GB): The sweet spot for most homelabbers. Enough for Proxmox with a couple of VMs and a decent stack of Docker containers. This is where most people should start.
  • 64GB (2x 32GB): Go big or go home. If you're running Proxmox with multiple VMs, a Kubernetes cluster, databases, or anything memory-hungry, this is the way. The price difference between 32GB and 64GB is small enough that you might as well just max it out.

My recommendation? Just go straight to 64GB. A pair of 32GB DDR4 SO-DIMMs costs about $80 to $100 AUD these days. For an extra $30-40 over 32GB, you'll never have to think about RAM again.

Where to Buy

Look for major brands — Kingston, Crucial, Samsung, SK Hynix, or Corsair. Here's where to shop:

  • Amazon AU — Usually the cheapest for new kits. Search for "64GB DDR4 SO-DIMM kit" and sort by price.
  • eBay — Great for pulled-from-server sticks. Samsung and SK Hynix modules pulled from laptops are often dirt cheap and work perfectly.
  • Crucial's website — Use their compatibility scanner to find the exact right stick for your model. Takes the guesswork out of it.
  • MSY, Umart, Scorptec — Aussie retailers if you want local stock and fast shipping.

Tools You'll Need

One Phillips head screwdriver. That's it. Seriously.

You don't need an anti-static wristband for a quick RAM swap — just touch the metal case of the PC before handling the sticks to discharge any static. Don't do this on carpet in your socks and you'll be fine.

Step-by-Step: Installing the RAM

Here's the full process. Should take you about two minutes once you've done it before.

  1. Shut down the PC and unplug the power cable. Give it 30 seconds to discharge.
  2. Flip it upside down. You'll see a single Phillips screw holding the bottom cover on. Some models have a thumbscrew you can turn by hand.
  3. Undo the screw and slide the bottom cover towards the front of the machine. It'll pop right off.
  4. Locate the RAM slots. You'll see one or two SO-DIMM sticks sitting in their slots with metal clips on each side. They're usually right in the middle, hard to miss.
  5. Remove the old RAM. Push the metal retention clips on each side of the stick outward (away from the stick). The stick will pop up at about a 30-degree angle. Gently pull it out at that angle.
  6. Repeat for the second stick if there is one.
  7. Insert the new RAM. Line up the notch on the stick with the notch in the slot — it only goes in one way, so you can't get it wrong. Slide the stick in at a 30-degree angle, then push it down flat until the metal clips click into place on both sides.
  8. Install the second stick in the other slot the same way.
  9. Put the cover back on. Slide it into place and tighten the screw.
  10. Plug in and boot up.
Don't force it: The sticks should slide in smoothly. If you're having to push hard, check you've got the notch lined up correctly. Forcing a stick in backwards will damage the slot and the module.

Verifying the Upgrade

Once the machine boots, you want to confirm all the RAM is being recognised. Here's how to check depending on what you're running:

In the BIOS (any OS):

  1. Power on the machine and press F10 repeatedly to enter BIOS setup.
  2. Look for "System Memory" or "Installed Memory" on the main info screen.
  3. It should show your total — e.g., 65536 MB for 64GB.

In Linux / Proxmox:

# Quick check
free -h

# Detailed info per stick
sudo dmidecode -t memory | grep -A5 "Memory Device" | grep -E "Size|Speed|Manufacturer"

In Windows:

  • Right-click the Start button > System. Your installed RAM shows under "Device specifications".
  • Or open Task Manager > Performance > Memory for a live view including speed and slots used.

Troubleshooting

If the machine won't boot or beeps at you after the upgrade, don't panic. Here's the usual suspects:

  • No display / continuous beeping: RAM isn't seated properly. Power off, open it back up, and reseat both sticks. Make sure they click in firmly.
  • Only half the RAM showing: One stick isn't being detected. Try each stick individually to find the dud. Could be a faulty stick or a dirty contact — try giving the gold contacts a gentle wipe with a clean, dry cloth.
  • Machine boots but is unstable / blue screens: The RAM speed might not be compatible with your board. Double-check you bought the right speed for your model generation (DDR4-2400 for G3, DDR4-2666 for G4/G5, DDR4-3200 for G6). Faster-rated RAM should downclock automatically, but occasionally a board is picky.
  • BIOS shows RAM but OS doesn't see all of it: Make sure you're running a 64-bit operating system. A 32-bit OS can only address about 3.5GB regardless of what's physically installed.
Still stuck? Try a BIOS update. HP publishes BIOS updates on their support site — search for your model number. An older BIOS sometimes doesn't recognise 32GB sticks, but a newer version sorts it out.

Keep the Old RAM

Don't chuck the old sticks. They're handy for troubleshooting if you ever suspect a RAM issue down the track. Chuck them in an anti-static bag (or just a zip-lock bag) and stash them in a drawer. If you've got a second mini PC in your future, you've already got RAM for it too.

What's Next?

Now that your machine is maxed out on RAM, it's ready for some serious work. If you haven't already, check out the rest of the homelab series:

64GB of RAM in a box that costs twenty bucks a year to run. Not bad for a two-minute upgrade with a single screwdriver.