HP EliteBook 840 G5 Upgrade Guide: RAM, SSD and CPU

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

This guide covers what you can upgrade in the HP EliteBook 840 G5: memory, the SSD and the processor. The short answer: you can fit up to 32 GB of DDR4 and swap the single M.2 2280 SSD (documented up to 1 TB), but the CPU should be treated as fixed.

At a glance

  • RAM: 2 DDR4 SO-DIMM slots, up to 16 GB each and 32 GB total
  • RAM runs at DDR4-2400 with 8th-gen CPUs and DDR4-2133 with 7th-gen CPUs
  • Storage: one M.2 2280 slot taking PCIe Gen3 x4 NVMe or SATA drives, documented up to 1 TB
  • There is no 2.5 inch bay or optical drive, so a new SSD replaces the old one
  • CPU: low-power U-series chips that are normally soldered, so plan on keeping the one you have
DDR4 SO-DIMM memory slot2 × DDR4 SO-DIMM · up to 32 GB total · 2400 MT/s
M.2 2280 SSD slotSSD M.2 2280 (NVMe / SATA) · up to 1 TB
2 × SO-DIMM · DDR4up to 32 GB totalM.2 2280 SSD slotSSD M.2 2280 (NVMe / SATA) · up to 1 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.

2018201920202021202220232024202520262027Today11 · Release · 2018
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDate
Release
First available to buy.		 2018 Estimate Inferred from the HP QuickSpecs revision history (V1 to V2 update on 2018-02-12), so early 2018 at the latest. HP's own launch date was not found, and a LaptopMedia review dated 2018-05-10 shows the laptop was on sale by then.
Source ↗

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

RAM: two DDR4 SO-DIMM slots, up to 32 GB

The EliteBook 840 G5 has two user-accessible DDR4 SO-DIMM slots (260-pin, 1.2 V) and no soldered memory. The maximum is 16 GB per module, so 32 GB in total. HP lists 4, 8, 12, 16, 20, 24 and 32 GB configurations built from 4, 8 and 16 GB modules. Use standard unbuffered, non-ECC modules.

Speed depends on the processor. Laptops with 8th-gen CPUs run memory at DDR4-2400, and those with 7th-gen CPUs run it at DDR4-2133. Kingston's page lists modules rated up to 3200 MT/s, but that is the module's rating. HP says this laptop runs at 2133 or 2400, so faster modules will be downclocked and gain you nothing.

Two things to watch. If you install only one module, it must go in the socket labeled 1. HP also says to update to the latest BIOS before adding memory, because skipping this may cause system problems. Mixed-size setups such as 16 GB plus 4 GB are listed as supported, but a mismatched pair may not run fully dual-channel, so two matching modules are the safest choice.

Buying tips

  • Buy DDR4 SO-DIMM, unbuffered, non-ECC, 1.2 V.
  • Two matching modules (for example 2 x 16 GB) give the best chance of dual-channel operation.
  • Don't pay extra for modules faster than DDR4-2400; they will be downclocked.
  • Check whether your laptop has a 7th-gen or 8th-gen CPU to know which speed to expect.

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Storage: one M.2 2280 slot, NVMe or SATA, up to 1 TB

There is a single M.2 2280 slot (22 mm wide, about 2.3 mm tall). It accepts either a PCIe Gen3 x4 NVMe drive (HP quotes up to 2800 MB/s read and 1600 MB/s write) or a SATA M.2 drive (up to 520 MB/s read and 450 MB/s write). HP's documented maximum is 1 TB. There is no 2.5 inch bay and no optical drive, so you can't add a second drive. Upgrading means replacing the existing SSD, so plan on cloning your data or doing a fresh install.

Kingston's page lists the interface as PCIe Gen 4 and Gen 5. HP's documents only specify Gen3 x4, so a Gen4 or Gen5 drive would at best run at Gen3 speed. Don't pay extra for one.

Factory drives varied, from 128 GB SATA up to 1 TB NVMe, and HP's own lists differ slightly between documents. Some units shipped with Opal 2 or FIPS 140-2 security drives, which may be tied to the configuration. HP's documents don't say whether the slot handles both SATA and NVMe in every configuration, so check your current drive type and the BIOS before buying.

Buying tips

  • Choose an M.2 2280 drive; check whether it is NVMe or SATA to match your needs.
  • A PCIe Gen3 x4 NVMe drive is the fastest option this slot supports.
  • Skip Gen4 and Gen5 drives; they run at Gen3 speed here.
  • If your laptop has an Opal 2 or FIPS drive, check how it is configured before swapping it.
  • Keep the old SSD, or a clone of it, until you've confirmed the new drive works.

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How to upgrade

Before you start

  • Check which processor your laptop has (7th-gen or 8th-gen), since that sets the RAM speed.
  • Note which type of SSD is installed (NVMe or SATA) before you buy a replacement.
  • Update the BIOS to the latest version before adding memory, as HP advises.
  • Back up your files, and make a drive image or clone if you're replacing the SSD.
  • Keep the owner's manual or HP's Maintenance and Service Guide handy for exact disassembly steps.
  • If your laptop has a security drive (Opal 2 or FIPS 140-2), check whether it is tied to the configuration before swapping it.

Steps

  1. Back up your data
    Copy important files elsewhere. If you're replacing the SSD, make a full clone or a recovery plan, because the laptop has only one drive slot.
  2. Update the BIOS
    Install the latest BIOS from HP before adding memory. HP warns that skipping this may cause various system problems.
  3. Power off and unplug
    Shut the laptop down completely, not just to sleep. Unplug the charger and any other cables or accessories.
  4. Ground yourself
    Touch a bare metal surface or use an anti-static strap before handling components, and hold modules and drives by their edges.
  5. Open the case
    Follow the owner's manual or HP's Maintenance and Service Guide for the exact way to remove the bottom cover and, if needed, disconnect the battery.
  6. Install the new part
    For memory, fit the module into the slot; if you use only one, put it in the socket labeled 1. For storage, remove the old M.2 2280 SSD and fit the new one in the same slot. Check the manual for how it is secured.
  7. Close up and reconnect
    Refit the cover and any screws, then reconnect power.
  8. Check that the laptop sees the part
    Start the laptop and open the BIOS setup to confirm the new memory size or the new drive is detected. A new, blank SSD will need an operating system installed or restored from your clone.

Good to know

  • HP's documents don't name a CPU socket. Based on general knowledge, these U-series chips are normally soldered, so don't plan a CPU upgrade.
  • Kingston lists faster memory (up to 3200 MT/s) and PCIe Gen4/Gen5 SSDs. HP specifies DDR4-2133/2400 and PCIe Gen3 x4, so faster parts will run at the slower speeds.
  • HP's QuickSpecs versions list different processor sets, and the factory drive lists differ slightly between documents. Check what your own unit has.
  • Opal 2 and FIPS 140-2 drives may be tied to the factory configuration. Verify before swapping.
  • The memory card reader and the wireless card slots aren't confirmed here. See the service guide for details.
  • HP's service guide covers both the 840 and 846 G5 models.

Frequently asked questions

How much RAM can the HP EliteBook 840 G5 take?

Up to 32 GB, using two 16 GB DDR4 SO-DIMMs. Each slot takes a maximum of 16 GB.

What RAM speed does the EliteBook 840 G5 use?

DDR4-2400 with 8th-gen CPUs and DDR4-2133 with 7th-gen CPUs. Faster modules will work only at those speeds.

Can I upgrade the CPU in the EliteBook 840 G5?

Almost certainly not. HP's documents don't name a CPU socket. The 7th-gen and 8th-gen U-series chips used here are normally soldered to the board, so treat the processor as fixed.

Does the EliteBook 840 G5 support NVMe SSDs?

Yes. The M.2 2280 slot takes PCIe Gen3 x4 NVMe or SATA M.2 drives. Check your current drive type and the BIOS first, as HP doesn't say both work in every configuration.

Can I add a second SSD to the EliteBook 840 G5?

No. There is only one drive slot and no 2.5 inch bay, so a new SSD replaces the old one.

Do I need to update the BIOS before adding RAM?

HP recommends it. Install the latest BIOS before adding memory, as skipping this may cause various system problems.

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.