HP EliteBook 840 G8 Notebook PC upgrade guide

Updated Oct. 13, 2026 · Written from this device's verified specifications

The HP EliteBook 840 G8 is one of the easier business laptops to upgrade: memory and storage are both user-serviceable, and HP documents the procedure in its maintenance guide. The processor, however, is soldered down and can never be swapped. Below is what fits, what the limits are, and what to watch out for before you buy parts. Note that regional SKUs (2J3M3EA, 2J3M7UT, 5Z5B5EA and others) differ in CPU, panel, WWAN and smart-card options, but they all share the same memory and storage limits.

At a glance

  • RAM: 2 slots, DDR4-3200 SO-DIMM, up to 64 GB total (2 x 32 GB), non-ECC only
  • Storage: 1 x M.2 2280 NVMe (PCIe Gen3 x4), up to 2 TB validated; no 2.5-inch bay, no second drive slot
  • CPU: soldered 11th-Gen Intel Tiger Lake-UP3 — not upgradeable
2x DDR4-3200 SO-DIMM (non-ECC, unbuffered)2 × DDR4 SO-DIMM · up to 64 GB total · 3200 MT/s
1x M.2 2280 NVMe (PCIe Gen3 x4)SSD M.2 2280 (NVMe) · up to 2.048 TB
2 × SO-DIMM · DDR4up to 64 GB total1x M.2 2280 NVMe (PCIe Gen3 x4)SSD M.2 2280 (NVMe) · up to 2.048 TB
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.

20202021202220232024202520262027Today11 · Release · December 2020
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDate
Release
First available to buy.		 December 2020 Estimate Reported as going on sale 'towards the end of December 2020'; no precise day published. HP's Dec 2020 press-kit material targets early 2021, so some sources say Q1 2021.
Source ↗

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

Memory (RAM)

The EliteBook 840 G8 has two physical DDR4 SO-DIMM slots, both accessible once the bottom cover is off. There is no soldered memory on standard configurations. The maximum is 64 GB total, using two 32 GB modules.

What fits: DDR4-3200 (PC4-25600) SO-DIMMs running at 1.2 V. Only non-ECC, unbuffered modules are supported — server-style ECC or registered memory will not work. Slower DDR4-2933 or DDR4-2666 modules are fine, but they will run at their rated (lower) speed rather than 3200 MT/s.

Limits: 32 GB per module, 64 GB total. Mixed sizes work too (HP's service manual lists combinations such as 48 GB as 32 + 16), but matched pairs are better.

Watch out for: many 840 G8 SKUs ship with a single 16 GB stick running single-channel. Adding a second, identical 16 GB module restores dual-channel, which also helps integrated graphics performance — often the most worthwhile memory upgrade on this machine.

One point of confusion: some HP marketing data sheets (for example the 5Z5B5EA sheet) say 'Number of memory slots: 1'. That describes the shipped configuration, not the hardware — HP's service and upgrade documentation confirms two physical slots, so trust the service manual here.

Buying tips

  • Buy a matched pair (same size, same speed, ideally same brand) for dual-channel performance.
  • DDR4-3200 SO-DIMM, 1.2 V, non-ECC, unbuffered — nothing else will fit.
  • If your machine already has 1 x 16 GB, one extra 16 GB module is the cheapest real upgrade.

Storage (SSD)

There is exactly one storage slot: an M-key M.2 2280 slot wired for PCIe Gen3 x4 NVMe. There is no 2.5-inch bay, no SATA connector and no second M.2 slot for storage, so an upgrade means replacing (and cloning) the existing drive.

What fits: M.2 2280 (22 x 80 mm) NVMe SSDs. HP validates drives up to 2 TB. Some budget configurations ship with slower Gen3 x2 'Value' drives or 128 GB modules; any Gen3 x4 drive will work in the slot, and the slot itself is Gen3 x4.

Limits: 2 TB is the validated maximum. Larger modules may work but are unvalidated, and HP's part specifications use single-sided drives around 2.3 mm thick — stick to single-sided modules to be sure of clearance under the bottom cover.

Watch out for: the WLAN (A/E-key) and WWAN (B-key) M.2 slots inside the machine are for wireless cards, not storage, and won't accept an SSD. If your laptop shipped with the Intel Optane H10 drive (QLC plus 32 GB Optane), it depends on Intel RST/Optane drivers and specific partitions; swapping to a standard NVMe SSD is usually simpler. OPAL2 self-encrypting drives were also offered at purchase and are a good option if you need hardware encryption.

Since there is no second bay, plan the swap in advance: clone the old drive to the new one through a USB NVMe enclosure before opening the laptop, or reinstall from recovery media afterwards. A microSD slot is present on this generation, handy for extra file space but not as a boot/system drive.

Buying tips

  • Get an M.2 2280 NVMe (M-key) SSD — Gen3 x4 is the sweet spot; faster Gen4 drives add cost but run at Gen3 speeds here.
  • Prefer single-sided modules (about 2.3 mm thick) and stay at 2 TB or under for guaranteed compatibility.
  • Budget for a USB NVMe enclosure so you can clone the old drive before swapping.

How to upgrade

Before you start

  • Back up your data before touching anything.
  • Update the BIOS/firmware to the latest version from HP first, as a general precaution.
  • Power off the laptop completely and unplug the charger.
  • Ground yourself (or use an anti-static strap) to avoid static damage.
  • Open the case: the bottom cover is held by Torx/Phillips screws and needs careful prying. HP's maintenance guide instructs you to disconnect the internal battery first before handling memory or the SSD. Check the owner's manual for exact disassembly steps for your SKU.
  • Install the new part, then reconnect the battery and close the case.
  • Power on and check that the BIOS/firmware recognises the new memory or drive (and that the full capacity is reported).

Steps

  1. Before you start
    Back up your data, update the BIOS/firmware from HP, power off and unplug the charger, and ground yourself. Read the owner's manual for your specific SKU first.
  2. Open the case
    Remove the Torx/Phillips screws on the bottom cover and carefully pry it loose. Disconnect the internal battery before touching any components — this is what HP's maintenance guide requires.
  3. Install the part
    For RAM: insert the SO-DIMM at an angle and press it down until the clips click. For the SSD: slide the M.2 2280 drive into the slot and secure it as shown in the manual. Both slots are user-accessible.
  4. Close up and verify
    Reconnect the battery, refit the bottom cover, then power on and confirm in the BIOS/firmware that the new memory or SSD is detected at the full capacity.

Good to know

  • Regional SKUs differ in CPU, panel, WWAN and smart-card options; memory and storage limits are the same across all 840 G8 variants.
  • Slower DDR4-2933/2666 modules work but run at their rated speed, not 3200 MT/s.
  • Drives larger than 2 TB and Optane H10 setups carry caveats described in the storage section.

Frequently asked questions

How much RAM can the HP EliteBook 840 G8 take?

Up to 64 GB total, using two 32 GB DDR4-3200 SO-DIMMs. It has two physical memory slots, even though some HP marketing sheets list '1 memory slot' for the shipped configuration.

Does the EliteBook 840 G8 support 64 GB of RAM?

Yes. The service manual confirms two customer-accessible slots supporting up to 64 GB of DDR4-3200 memory in dual channel.

Can you upgrade the CPU in an EliteBook 840 G8?

No. The 11th-Gen Intel Tiger Lake-UP3 processors (i5-1135G7, i5-1145G7, i7-1165G7, i7-1185G7) are soldered to the board. There is no socket and no CPU upgrade path.

Does it support ECC or registered memory?

No. Only non-ECC, unbuffered DDR4 SO-DIMMs at 1.2 V are supported.

How many SSDs can the EliteBook 840 G8 hold?

One. There is a single M.2 2280 NVMe slot (PCIe Gen3 x4). There is no 2.5-inch bay, no SATA port and no second M.2 storage slot, so upgrades mean replacing the existing drive.

What is the maximum SSD size supported?

HP validates drives up to 2 TB in the M.2 2280 slot. Larger modules may work but are unvalidated; single-sided drives are recommended for clearance under the bottom cover.

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.