HP EliteBook 840 14 inch G9 Upgrade Guide: RAM and SSD

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.

RAM: two DDR5 SO-DIMM slots, up to 64 GB

The laptop has two DDR5 SO-DIMM slots and no soldered memory. The largest module listed is 32 GB, so two 32 GB modules give a maximum of 64 GB. Kingston lists 262-pin non-ECC unbuffered SO-DIMMs for this model. HP shipped it with 8 GB (1x8), 16 GB (1x16 or 2x8), 32 GB (1x32 or 2x16) and 64 GB (2x32).

Most HP documents give the memory speed as DDR5-4800, but one HP datasheet says the system runs at 5600 MT/s. HP's documents don't say which configuration that refers to, so check your exact SKU. Kingston lists both 5600 and 4800 modules for this model and says faster memory will clock down to the speed your processor supports. If you mix modules of different speeds, the system runs at the lower speed.

Dual-channel mode needs a matched pair of modules. A single module runs single-channel, which is slower. HP recommends HP-branded memory because some third-party modules are non-standard. The documents we checked list only non-ECC unbuffered modules and don't say whether ECC or registered memory works.

Buying tips

• Buy a matched pair (for example 2 x 16 GB) rather than a single module so you get dual-channel.
• Look for DDR5 SO-DIMM, non-ECC, unbuffered. Laptop-sized DDR4 or desktop DIMMs will not fit.
• Don't pay extra for 5600 MT/s unless your SKU's datasheet confirms it; 4800 MT/s is the figure most HP documents give.
• If you already have one module installed, adding an identical second one is the simplest way to reach dual-channel.
• Consider HP-branded memory if you want to follow HP's recommendation.

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

There is a single internal drive slot: an M.2 2280 NVMe slot with a PCIe Gen 4 x4 connection. Kingston notes it takes single-sided 2280 drives. HP lists 2 TB as the maximum capacity. None of the documents we checked mention SATA support or a 2.5 inch drive bay.

Because it is the only slot, a bigger SSD means replacing the existing drive. Plan to clone your current drive to the new one or reinstall Windows from scratch. HP's factory options were 256 GB, 512 GB, 1 TB and 2 TB Gen4 x4 drives, self-encrypting 256 GB and 512 GB drives, and 256 GB and 512 GB Value NVMe drives.

The Value drives are slower. The 256 GB Value drive is rated at about 2000 MB/s read and 900 MB/s write, against 4000/2000 MB/s for the 256 GB Gen4 drive and up to 6400 MB/s read for 512 GB and larger. If you want to keep your original drive's speed, check which type is currently fitted.

Don't confuse the storage slot with the M.2 3052 Key B slot used by the optional wireless WAN modem. That is not a storage slot.

Buying tips

• Choose a single-sided M.2 2280 NVMe SSD; avoid double-sided drives.
• A PCIe Gen 4 drive suits the slot, but check the drive's own speed rating if performance matters.
• Expect less usable space than the label says. Formatting takes some, and HP's recovery software reserves up to 35 GB.
• A USB-to-M.2 enclosure or cloning cable makes copying your old drive easier.
• Keep the old SSD as a backup until you've confirmed the new one boots and works.

How to upgrade

Before you start

• Check the HP maintenance and service guide for your exact SKU. One HP datasheet snippet appears to describe the memory as not customer-accessible, but the text is too corrupted to rely on, while a hands-on review says the slots are upgradeable.
• Back up your files and, if you use it, save your BitLocker recovery key before changing the drive.
• Check your SKU's datasheet for the memory speed (4800 or 5600 MT/s) before buying RAM.
• Note the type of SSD currently fitted so you know what you are replacing.
• Have a small screwdriver and a clean, static-free workspace ready. Use the owner's manual or maintenance guide for the exact screws and disassembly order.

Steps

1. Back up your data
   Copy your important files to external storage or the cloud. If you plan to clone the SSD, make sure the clone software and a cable or enclosure are ready.
2. Power off and unplug
   Shut the laptop down fully (not sleep or hibernate), unplug the charger and disconnect any accessories.
3. Ground yourself
   Touch a bare metal surface or wear an anti-static strap before handling memory or drives. Hold parts by the edges.
4. Open the case
   Follow HP's maintenance and service guide for your SKU to remove the bottom cover. A hands-on review reports the memory sits under a metal bracket, so expect to move that out of the way. Disconnect the battery if the guide tells you to.
5. Install the RAM
   Fit the SO-DIMM modules into the slots as the guide shows, using a matched pair for dual-channel. Make sure each module is fully seated and locked in place.
6. Replace the SSD
   Remove the existing M.2 2280 drive as shown in the guide and fit the new single-sided NVMe drive in its place. Secure it the way the original was fixed.
7. Close the case
   Refit any bracket and the bottom cover, reinstall all screws and reconnect the battery if you disconnected it.
8. Check that the system sees the new parts
   Power on and open the BIOS setup screen using the key HP shows at startup. Confirm the total memory and the new drive appear. If you replaced the SSD, restore your clone or reinstall Windows, then check the capacity in Windows.

Good to know

• One HP datasheet may describe the memory slots as not customer-accessible, but its text is too corrupted to rely on. Check the HP maintenance guide for your SKU before buying parts.
• Memory speed is unconfirmed: most HP documents say DDR5-4800, one says 5600 MT/s.
• ECC and registered memory are not offered for this model, and HP's documents don't say whether they work.
• Card readers and the exact release or screw details are not covered here, so follow HP's guide for your SKU.
• HP recommends HP-branded memory; some third-party modules may not behave as expected.

Frequently asked questions

How much RAM can the HP EliteBook 840 G9 take?

Up to 64 GB, using two 32 GB DDR5 SO-DIMMs. Memory is not soldered, so both slots are available.

What type and speed of RAM does the EliteBook 840 G9 use?

DDR5 SO-DIMM. Most HP documents say DDR5-4800, but one datasheet lists 5600 MT/s, so check your SKU. Faster modules will run at the speed your processor supports.

Do I need to install RAM in pairs?

For dual-channel performance, yes: use a matched pair. A single module works but runs single-channel. If you mix speeds, the system runs at the lower one.

What size SSD does the EliteBook 840 G9 support?

One M.2 2280 NVMe slot with PCIe Gen 4 x4, taking single-sided drives. HP lists 2 TB as the maximum capacity.

Can I add a second SSD or a 2.5 inch drive?

None of the documents we checked mention a second storage slot or a 2.5 inch bay. The M.2 slot is the only internal drive slot, so you replace the existing SSD.

Can I upgrade the CPU in the EliteBook 840 G9?

HP's documents don't describe a CPU upgrade for this laptop. Treat the processor (for example the i5-1245U) as fixed and focus on RAM and storage.

Official documents and references

• HP Support: EliteBook 840 14 inch G9 specifications
  Memory, storage and configuration details from HP
• HP EliteBook 840 G9 datasheet
  Drive options, speeds and the WWAN card; lists 5600 MT/s memory
• HP EliteBook 840 G9 i5 datasheet (Bechtle)
  DDR5-4800 memory and SSD options
• Kingston memory for HP EliteBook 840 G9
  Compatible DDR5 SO-DIMMs and SSD notes
• LaptopMedia review: HP EliteBook 840 G9
  Hands-on look at the RAM and SSD slots