HP EliteDesk 800 G6 Small Form Factor PC upgrade guide

Lifecycle and support

A current model: sold new and supported.

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

Memory (RAM)

The EliteDesk 800 G6 SFF has four desktop DDR4 DIMM sockets (288-pin UDIMM). Laptop SO-DIMM modules will not fit. The memory is non-ECC and unbuffered: this is not a Xeon platform, so server-style ECC or registered modules are not supported, and x4-based modules are unsupported (x8 and x16 modules are fine). Nothing is soldered, so all four slots are yours to use.

Each slot accepts up to 32 GB modules, giving a stated maximum of 128 GB (4 x 32 GB). Be aware that HP's own documentation conflicts here: some text in the service guide talks about lower-density memory chips, which does not sit well with 32 GB modules. The 128 GB figure appears in both the service guide and HP's own product datasheet, but it is worth checking with HP before you spend money on 32 GB DIMMs.

Speed is the other catch. DDR4-3200 modules fit and work, but the real transfer rate is set by the processor, not the stick. With an i7 or i9 the memory runs at up to 2933 MT/s; with an i3, Pentium and some i5 configurations it tops out at 2666 MT/s. Paying extra for fast modules is only worthwhile if your CPU can actually use the speed. The slots are laid out as DIMM1/DIMM2 on one channel and DIMM3/DIMM4 on the other, so fitting matched pairs lets you run dual-channel mode.

One last housekeeping note: you need a 64-bit operating system to use more than 4 GB. With a 32-bit Windows install, part of your memory simply will not be usable.

Buying tips: match the speed to your CPU (DDR4-2666 or DDR4-2933 is often the sensible buy), prefer matched kits for dual channel, and buy unbuffered non-ECC desktop UDIMMs only.

Buying tips

• Desktop 288-pin DDR4 UDIMM, non-ECC, unbuffered
• 2666 or 2933 MT/s is the sweet spot for most owners
• Matched pairs let you use both memory channels

Storage (SSD and hard drive)

There is plenty of room for drives here. The star is a single M.2 2280 slot for a PCIe NVMe SSD, using PCIe 3.0. HP ships this machine with M.2 drives from 128 GB up to 2 TB, and Intel Optane H10 is supported, so a standard M.2 2280 NVMe drive is a straightforward upgrade.

Watch the length. HP's expansion table is confusing here: it mentions 2230/2242 sizes, which belong to the separate M.2 slot used for the Wi-Fi/Bluetooth card. That WLAN slot is already occupied and is not for storage. Plan for a 2280 drive; if you somehow want to use a shorter 2242 drive, you would need some kind of riser or adapter.

For bulk storage there are three SATA bays: one 2.5-inch bay and two 3.5-inch bays, each rated at up to 2 TB as HP configures them. The factory list covers 500 GB to 2 TB 7200 rpm hard drives, 5400 rpm options and self-encrypting (SED/FIPS OPAL 2) drives in the 2.5-inch bay. HP does not document a thickness limit for 2.5-inch drives, so check clearance yourself if you buy a tall model. The slim 9.5 mm optical bay is also free if you want to use that space.

Two caveats worth knowing. First, HP's DriveLock feature does not work with self-encrypting (SED/OPAL) or Optane-based storage. Second, up to 36 GB of your system disk is reserved for HP recovery software, so factor that in when you plan a clean install or move to a smaller drive.

Buying tips: an M.2 2280 NVMe SSD is the easiest speed boost, SATA drives are the cheap way to add bulk, and stay within 2 TB per bay if you want to stick to HP's supported configurations.

Buying tips

• M.2 2280 PCIe NVMe SSD for the fastest option
• Up to 2 TB per SATA bay as officially configured
• Skip SED/OPAL or Optane drives if you rely on DriveLock

Processor (CPU)

The CPU is socketed and user-replaceable: an LGA 1200 socket on Intel's Q470 platform. That socket physically takes both 10th and 11th Gen Intel chips, but HP supports 10th Gen Comet Lake only. The supported list is Pentium Gold G6500; Core i3-10100 and i3-10300; Core i5-10500, i5-10600 and i5-10600K; Core i7-10700 and i7-10700K; and Core i9-10900 and i9-10900K. 11th Gen Rocket Lake processors are not supported even though they use the same socket, so do not be tempted by a bargain 11th Gen chip.

Power is the real limit. Most of these CPUs are 65 W parts, which the standard 260 W power supply handles. The unlocked K-series chips are rated at 125 W and belong with the 350 W power supply option. If your machine has the 260 W unit, stick to 65 W processors. And if you have added a discrete graphics card as well as a K-series CPU, check the power supply before you commit to that combination.

Before buying any processor, check HP's BIOS CPU support list, since BIOS revisions determine what the board will accept. The same applies to enterprise machines bought second-hand: HP's BIOSphere and Sure Start features, plus TPM 2.0, can leave settings locked down by a previous owner.

Buying tips: the i7-10700 is usually the sweet spot for a big jump without needing a new power supply; a K-series chip only makes sense with the 350 W PSU; and always confirm support in HP's BIOS list first.

Buying tips

• 10th Gen Comet Lake only, despite the shared LGA 1200 socket
• 125 W K-series CPUs need the 350 W PSU
• Check HP's BIOS CPU support list before you buy

How to upgrade

Before you start

• Back up your data first, and keep your recovery media handy.
• Shut the PC down properly and unplug the power cable and peripherals.
• Ground yourself (touch the metal chassis or use an anti-static wrist strap) before touching components.
• Photograph the inside before you unplug anything, so cabling goes back the way it was.

Steps

1. General installation outline
   The exact disassembly varies by part and chassis, so use HP's owner's manual for the step-by-step for your machine. As a safe general order: 1. Back up your data and create recovery media. 2. Shut down, unplug the power cord and remove the side panel as the manual describes. 3. Ground yourself to the chassis before handling the new part. 4. Install the component: seat memory modules firmly until the clips click, screw an M.2 2280 SSD into its post, mount a SATA drive in a bay and connect power and data cables, or (for a CPU) release the socket lever, lift the old chip and seat the new one without touching the pins. The manual shows the exact latches and screws for your chassis. 5. Do a quick visual check that nothing is loose and no cable is fouling a fan, then refit the panel. 6. Plug in, power on and enter the BIOS/firmware to confirm the new memory, drive or processor is detected at the expected size and speed. 7. Finish setup in your operating system: format any new drive, install drivers if prompted, and remember that up to 36 GB of a system disk is reserved for HP recovery.
2. Setting up the memory
   The four slots are DIMM1 through DIMM4, with DIMM1/DIMM2 on one channel and DIMM3/DIMM4 on the other. For matched pairs, install them one per channel so the machine can run in dual-channel mode. The system switches between single-channel, dual-channel and flex mode automatically depending on what you fit.
3. Setting up storage
   If you are moving to a bigger system disk, plan for the recovery partition in advance: up to 36 GB of the disk is reserved for HP recovery software. HP's DriveLock protection is not available on self-encrypting (SED/OPAL) or Optane-based drives, so decide whether that matters before you buy. In the BIOS, confirm the NVMe drive appears and check that SATA ports are enabled.

Good to know

• HP's documentation conflicts on the memory density needed for 32 GB modules: verify with HP before buying four 32 GB DIMMs.
• HP's expansion table garbles the M.2 lengths, while the supported drive list clearly covers M.2 2280 NVMe SSDs up to 2 TB; plan for 2280 drives.
• HP does not document a thickness limit for 2.5-inch drives, so check physical clearance yourself.

Frequently asked questions

How much RAM can the HP EliteDesk 800 G6 SFF take?

Up to 128 GB, using four 32 GB DDR4 UDIMMs in its four slots. HP's documentation is inconsistent on the memory chip density needed for 32 GB modules, so verify with HP before buying four of them. You also need a 64-bit operating system to see more than 4 GB.

Does it support DDR4-3200 memory?

DDR4-3200 modules fit and work, but the machine will not run them at full speed. The CPU sets the limit: up to 2933 MT/s with an i7 or i9, and 2666 MT/s with an i3, Pentium and some i5 configurations. Buying faster modules than your CPU can use gives you no benefit.

Does it support ECC or registered server memory?

No. The EliteDesk 800 G6 SFF uses non-ECC, unbuffered desktop DDR4 UDIMMs only. Registered and ECC server modules are not supported, and x4-based modules are unsupported too (x8 and x16 are fine).

Can I add an NVMe SSD, and which M.2 size fits?

Yes. The storage slot takes an M.2 2280 PCIe NVMe SSD over PCIe 3.0; HP ships drives from 128 GB to 2 TB and Intel Optane H10 is supported. The smaller 2230/2242 M.2 slot is for the WLAN card and is already occupied. Note that DriveLock does not work with Optane or self-encrypting drives.

Does the HP EliteDesk 800 G6 SFF support 11th Gen Intel CPUs?

No. The LGA 1200 socket physically accepts them, but HP supports 10th Gen Comet Lake only, from the Pentium Gold G6500 up to the Core i9-10900K. Check HP's BIOS CPU support list before buying any processor.

Can I fit a Core i7-10700K or i9-10900K?

These 125 W unlocked chips are on HP's supported list, but only with the 350 W power supply. If your machine has the 260 W unit, stick to the 65 W processors such as the i7-10700. Adding a discrete graphics card as well makes a bigger PSU even more important.

Official documents and references

• HP support document for the EliteDesk 800 G6 SFF
  HP's own support page: supported M.2 NVMe drives, Optane H10 support and the DriveLock limitation with SED/OPAL and Optane storage.
• PDF HP EliteDesk 800 G6 SFF datasheet (PDF)
  Manufacturer datasheet: 128 GB maximum memory, supported 10th Gen CPU list, power supply options and expansion slots.
• PDF HP EliteDesk 800 G6 QuickSpecs (PDF)
  HP QuickSpecs: CPU-dependent memory speeds (2933/2666 MT/s), storage configurations and the 64-bit OS requirement.
• HP EliteDesk 800 G6 SFF service guide
  Service manual: DIMM slot layout and channel pairing, supported memory types and module limits, and the disassembly procedures to follow.