HP EliteDesk 800 G1 SFF Upgrade Guide: RAM, SSD and CPU

Updated Oct. 10, 2026 · Written from this device's verified specifications

This guide covers adding memory, a bigger drive or a faster processor to the HP EliteDesk 800 G1 Small Form Factor PC. The short version: it takes up to 32 GB of full-size DDR3 across four slots, stores data on SATA drives only (there is no M.2 slot), and has a socketed Haswell-generation CPU.

At a glance

  • RAM: 4 full-size DDR3/DDR3L DIMM slots, up to 32 GB total, up to 1600 MT/s.
  • Memory must be unbuffered, non-ECC, built from x8 or x16 chips.
  • Storage: one internal 3.5" and one internal 2.5" SATA bay; no M.2 slot.
  • CPU: socketed LGA 1150 (Intel Q87) for 4th-gen Core (Haswell) chips; no maximum wattage is documented.
  • Do not use specs for the Desktop Mini or Ultra-Slim 800 G1; they differ.
DDR3/DDR3L DIMM (full-size, 240-pin)4 × DDR3 DIMM · up to 32 GB total · 1600 MT/s
Internal 3.5" SATA bayHDD / SSD 3.5" (SATA)
Internal 2.5" SATA bayHDD / SSD 2.5" (SATA)
4 × DIMM · DDR3up to 32 GB totalInternal 3.5" SATA bayHDD / SSD 3.5" (SATA)Internal 2.5" SATA bayHDD / SSD 2.5" (SATA)
Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

Lifecycle and support

A current model: sold new and supported.

20132015201720192021202320252027Today11 · Release · 2013
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDate
Release
First available to buy.		 2013 Estimate Inferred from HP documentation dates (SFF spec 1st Edition July 2013; hardware guide first edition April 2013), not a launch announcement; probably mid-2013
Source ↗

Dates not listed haven't been published by the manufacturer or a reliable third party.

Memory (RAM) upgrade

The SFF has four full-size 240-pin DDR3/DDR3L DIMM sockets (not laptop-style SO-DIMMs). HP lists a maximum of 32 GB in dual-channel mode. HP does not state a per-module limit, but 32 GB over four slots implies 8 GB per DIMM. At least one DIMM comes preinstalled, and all four sockets can be filled.

Modules must be unbuffered, non-ECC, 1.35 V or 1.5 V, and carry standard JEDEC SPD data. Single- and double-sided DIMMs work, and so do modules built from x8 or x16 chips. Modules built from x4 chips are not supported, and HP warns the PC will not operate properly with unsupported DIMMs. The top speed is PC3-12800 (DDR3-1600, CL11), but the speed you actually get depends on your CPU, and lower-end processors may run memory slower.

DIMM1 and DIMM2 sit on channel B, and DIMM3 and DIMM4 on channel A. Fill both channels for dual-channel performance.

Buying tips

  • Buy DDR3 or DDR3L desktop DIMMs, not SO-DIMMs and not DDR4.
  • Choose unbuffered non-ECC modules; avoid registered or server-style modules, which are often x4-based.
  • Match modules in pairs, one per channel, for dual-channel mode.
  • DDR3-1600 (PC3-12800) is the fastest speed worth paying for.

Storage (SSD and hard drive) upgrade

The main drive bays are one internal 3.5" SATA bay and one internal 2.5" SATA bay. The board has three SATA ports in total, which also serve the slimline optical bay, and HP also documents an external 3.5" bay. A 2.5" SATA SSD is the simplest speed upgrade; a bracket or adapter may be needed if you want it in the 3.5" bay.

There is no M.2 slot on the SFF. M.2 entries you may see in HP's spec sheet belong to the Desktop Mini and Ultra-Slim versions. An NVMe drive would need a PCIe adapter card, and whether this PC can boot from NVMe is unconfirmed. The listings also disagree on the number of PCIe slots (two x16 plus one or two x1, depending on the document), so check what your own unit has before buying an adapter.

No maximum drive capacity or 2.5" drive thickness is documented. HP's factory options include hard drives up to 1 TB and SSDs starting at 120 GB, so larger SATA drives are likely to work, but that is not confirmed.

Buying tips

  • Buy a SATA SSD, not an M.2 one.
  • Check the drive's thickness if it is not a standard slim 2.5" model, as the bay's limit isn't documented.
  • Keep your old drive connected or cloned until the new one boots reliably.
  • Only buy a PCIe NVMe adapter if you accept that booting from it is unverified.

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How to upgrade

Before you start

  • Back up your files, or clone your current drive, before opening the PC.
  • Check which CPU you have, as it affects the memory speed you will get.
  • Have the owner's manual or HP Hardware Reference Guide to hand for exact disassembly steps.
  • Use a clean, static-free work area and a Phillips screwdriver.

Steps

  1. Back up your data
    Copy important files to an external drive or the cloud, especially if you are replacing the system drive.
  2. Power off and unplug
    Shut the PC down fully, unplug the power cable and all other cables, and hold the power button for a few seconds to drain residual charge.
  3. Ground yourself
    Touch bare metal on the chassis or wear an anti-static strap before handling components. Hold memory modules and drives by their edges.
  4. Open the case
    Remove the side access panel as described in the owner's manual. Lay the PC on its side if that gives easier access.
  5. Install the part
    For RAM, push DIMMs into the sockets, filling both channels, until the retaining clips close. For a drive, mount it in the 2.5" or 3.5" bay and connect SATA data and power cables. For a CPU, follow the HP manual and check HP's supported-CPU list first; take extra care with the socket and heatsink.
  6. Close the case and reconnect
    Refit the panel, reconnect the cables and power on.
  7. Check the BIOS
    Press the BIOS setup key at startup (shown on screen) and confirm the new memory total, drive or processor is detected before installing or restoring the operating system.

Good to know

  • The per-module RAM maximum isn't stated by HP; 8 GB per slot is inferred from the 32 GB total.
  • Memory speed depends on the installed CPU, and lower-end processors may support less than DDR3-1600.
  • No maximum 2.5" drive thickness or maximum drive capacity is documented; larger SATA drives are likely to work but aren't confirmed.
  • Booting from NVMe through a PCIe adapter is unverified on this model.
  • Listings disagree on the number of PCIe slots and on whether there are one or two internal 3.5" bays; check your own unit's layout.
  • No maximum CPU power rating is documented; check HP's supported-CPU list before buying a high-wattage processor.
  • Do not use specs for the Desktop Mini or Ultra-Slim 800 G1 (SO-DIMM, 16 GB maximum, M.2); they do not apply to the SFF.

Frequently asked questions

How much RAM can the HP EliteDesk 800 G1 SFF take?

Up to 32 GB in total across four DIMM slots, in dual-channel mode. The per-module limit isn't stated, but 32 GB over four slots implies 8 GB modules.

What type of RAM does the EliteDesk 800 G1 SFF use?

Full-size 240-pin DDR3 or DDR3L DIMMs, unbuffered and non-ECC, at 1.35 V or 1.5 V, up to DDR3-1600. Use x8 or x16 modules; x4 modules are not supported.

Does the EliteDesk 800 G1 SFF have an M.2 slot?

No. The SFF has no M.2 slot; M.2 specs in HP's documents refer to the Desktop Mini and Ultra-Slim models. Use a SATA drive, or an NVMe drive on a PCIe adapter, though booting from NVMe is unconfirmed.

Can I upgrade the CPU in the EliteDesk 800 G1 SFF?

Yes, the CPU is socketed (LGA 1150, Intel Q87 chipset) and supports 4th-gen Core (Haswell) Celeron, i3, i5 and i7 processors. HP doesn't document a maximum CPU wattage, so check HP's supported-CPU list before buying a high-power chip.

Can I use ECC memory in the EliteDesk 800 G1 SFF?

No. HP's system guide requires unbuffered non-ECC DIMMs, even though one processor listing mentions ECC support. Follow HP's guide.

How many drives can the EliteDesk 800 G1 SFF hold?

HP documents one internal 3.5" bay, one internal 2.5" bay, one external 3.5" bay and a slimline optical bay, with three SATA ports on the board. One listing shows two 3.5" bays, so layouts may vary by unit; check yours.

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.