HP EliteDesk 800 G3 Mini Upgrade Guide: RAM, SSD and CPU

Updated Oct. 8, 2026 · Written from this device's verified specifications

This guide covers adding RAM, a bigger SSD or a faster CPU in the HP EliteDesk 800 G3 Desktop Mini (35 W and 65 W versions). The short answer: RAM and storage are easy upgrades, while a CPU swap is limited to 7th-gen Core chips that match your chassis.

At a glance

  • RAM: 2 SODIMM slots, DDR4 non-ECC, up to 32 GB total (2 x 16 GB).
  • Storage: one 2.5" SATA bay plus one M.2 PCIe NVMe slot (2280 or 2230).
  • No 3.5" bay and no PCIe expansion slot.
  • CPU: 7th-gen Core i3/i5/i7 only, up to 65 W. Match 35 W (T-series) or 65 W to your chassis.
  • Memory runs at up to 2400 MT/s, but 2133 is the safe assumption.
SODIMM memory2 × DDR4 SO-DIMM · up to 32 GB total · 2400 MT/s
2.5" SATA bayHDD / SSD 2.5" (SATA)
M.2 PCIe NVMe slot (Turbo Drive)SSD M.2 2230 / M.2 2280 (NVMe)
LGA1151 CPU socketLGA1151 (6th/7th gen) · Core 7th gen · max 65 W
CPU · LGA1151max 65 W2 × SO-DIMM · DDR4up to 32 GB total2.5" SATA bayHDD / SSD 2.5" (SATA)M.2 PCIe NVMe slot (Turbo Drive)SSD M.2 2230 / M.2 2280 (NVMe)
Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

RAM: two SODIMM slots, up to 32 GB

The Mini has two customer-accessible SO-DIMM slots, one per memory channel. It takes 1.2 V DDR4, 260-pin, unbuffered non-ECC modules only. The maximum is 32 GB total, which means two 16 GB modules. Modules must use x8 or x16 DRAM chips; x4 modules are not supported. Single-channel, dual-channel and flex modes are chosen automatically, so matching pairs are the simplest way to get dual-channel.

Speed tops out at DDR4-2400, but the actual speed is set by the processor you have installed. HP's own documents are inconsistent here, quoting both DDR4-2133 and DDR4-2400, so treat 2400 as the ceiling and 2133 as the safe expectation.

One more disagreement: HP's service guide spare-parts list shows only 4 GB and 8 GB modules, while its spec sheets list 16 GB modules and a 32 GB maximum. HP also warns that the system may not operate properly with unsupported modules and advises buying HP memory.

Buying tips

  • Buy DDR4 SODIMM (laptop-size), not desktop DIMMs and not DDR3.
  • Choose non-ECC, unbuffered modules.
  • Buy a matched pair if you want dual-channel.
  • If 16 GB modules matter to you, expect them to work per HP's spec sheets, but remember the service guide only lists 4 GB and 8 GB spares.
  • 32-bit Windows can only use about 3 GB, so 64-bit Windows is needed to benefit from more RAM.

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Storage: 2.5" SATA bay plus an M.2 NVMe slot

There is one internal 2.5" bay running at SATA 6.0 Gb/s, which takes a 2.5" SATA SSD or hard drive. HP lists drives up to 1 TB, but that is a catalogue ceiling rather than a verified hardware limit. No thickness limit is documented, so check the drive's height before buying a thick one.

There is also one M.2 PCIe x4 slot (HP calls it Turbo Drive) for 2280 or 2230 drives, and HP's own SSD example is NVMe. HP's documents don't say which PCIe generation this slot runs at, or whether M.2 SATA drives work in it, so stick to NVMe drives.

The machine also has a separate M.2 2230 slot, but that is for the Wi-Fi card and is not for storage. There is no 3.5" bay and no PCIe expansion slot. HP reserves part of the system disk for recovery software (up to 16 GB on Windows 7 or 36 GB on Windows 8.1/10), so usable space will be a little lower.

Buying tips

  • For the M.2 slot, buy an NVMe drive in 2280 or 2230 size.
  • Avoid M.2 SATA drives for the storage slot; support is not confirmed.
  • For the 2.5" bay, a SATA SSD is the easy speed upgrade over a hard drive.
  • Check the thickness of any 2.5" drive before buying.
  • Drives larger than HP's 1 TB listing may well work, but that is not confirmed.

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CPU: 7th-gen Core, matched to your chassis

HP's documents list 7th-generation Core i3, i5 and i7 processors. The 65 W options include the i7-7700, i5-7500, i5-7600, i3-7100 and i3-7300. The 35 W T-series options include the i7-7700T, i5-7500T, i5-7600T and i3-7100T. The highest-rated listed CPU is 65 W.

HP marks T-series CPUs for 35 W models only and 65 W CPUs for 65 W models only. Do not put a 65 W CPU in a 35 W unit, because the cooling differs.

HP's documents don't name the socket or say whether 6th-gen CPUs are supported. These CPUs are generally understood to use LGA1151, but that is not confirmed by HP's documents here, so check the service guide or an HP parts lookup before buying.

Buying tips

  • First work out whether you have a 35 W or 65 W model, then buy only a matching CPU.
  • Stick to the 7th-gen i3/i5/i7 parts HP lists.
  • Don't buy a 6th-gen CPU expecting it to work; support is unconfirmed.
  • A faster CPU may also raise the memory speed you get, since the CPU sets it.

How to upgrade

Before you start

  • Find out whether your unit is the 35 W or 65 W version.
  • Back up your files, and have your Windows recovery media or licence details to hand.
  • Check which version of Windows you run: 64-bit is needed to use more than about 3 GB of RAM.
  • Keep the owner's manual or HP service guide open for exact disassembly steps.
  • Have a small screwdriver and an anti-static strap or a grounded metal surface ready.

Steps

  1. Back up your data
    Copy anything important to an external drive or cloud storage, especially before changing a storage drive.
  2. Power off and unplug
    Shut the PC down fully, unplug the power adapter and all cables, and wait a moment for it to settle.
  3. Ground yourself
    Touch bare metal or wear an anti-static strap before handling parts, and hold components by their edges.
  4. Open the case
    Follow the HP hardware reference guide or service guide for how to remove the access panel on the Mini. HP's service manual also covers installing an M.2 PCIe SSD.
  5. Install the part
    For RAM, fit the SODIMMs into the two slots. For storage, use the 2.5" bay or the M.2 storage slot (not the Wi-Fi slot). For a CPU, use only a model that matches your 35 W or 65 W chassis. Follow the manual for the exact procedure.
  6. Close up and reconnect
    Refit the access panel and reconnect the power and cables.
  7. Check the BIOS
    Start the PC and open the BIOS setup to confirm the new memory amount, drive or processor is detected before you reinstall or restore anything.

Good to know

  • HP's documents disagree on RAM speed (DDR4-2133 and DDR4-2400); treat 2133 as the safe assumption.
  • HP's service guide lists only 4 GB and 8 GB memory modules, while its spec sheets list 16 GB modules and a 32 GB maximum.
  • HP advises using HP memory and says unsupported modules may not work properly.
  • HP's 1 TB drive figure is a catalogue ceiling, not a verified limit. No 2.5" drive thickness limit is documented.
  • The M.2 slot's PCIe generation and M.2 SATA support are not stated.
  • The CPU socket is not named in HP's documents (LGA1151 is the generally understood socket), and 6th-gen CPU support is unconfirmed.
  • Never fit a 65 W CPU in a 35 W chassis.
  • The service guide is shared with other Mini models, so some details may differ for yours.

Frequently asked questions

How much RAM can the HP EliteDesk 800 G3 Mini take?

Up to 32 GB total, using two 16 GB DDR4 SODIMMs. HP's service guide only lists 4 GB and 8 GB spare modules, but its spec sheets list 16 GB modules and the 32 GB maximum.

What speed of RAM does it support?

Up to DDR4-2400, with the actual speed set by the CPU. HP's documents also mention DDR4-2133, so 2133 is the safe assumption.

Does it have an M.2 slot for an SSD?

Yes. One M.2 PCIe x4 slot takes 2280 or 2230 drives, and NVMe is the safe choice. HP doesn't state the PCIe generation or whether M.2 SATA drives work. The other M.2 2230 slot is for the Wi-Fi card and is not for storage.

Can I fit a 3.5" hard drive?

No. The Mini has no 3.5" bay. It has one 2.5" SATA bay and the M.2 slot.

Can I upgrade the CPU?

Probably, within limits. HP lists 7th-gen Core i3, i5 and i7 chips, and you must match the chassis: T-series for 35 W units and 65 W parts for 65 W units. HP's documents don't name the socket (these CPUs are generally LGA1151) or confirm 6th-gen support.

Can I add a graphics card?

No. The Desktop Mini has no PCIe expansion slot.

Official documents and references

This guide was written with AI assistance from the compatibility data PartsPrices verified against the manufacturer's documents. Always check your exact model and the owner's manual before buying or opening your computer.