HP EliteBook 840 G3 upgrades

Released 2016 · on sale

CPU is soldered (BGA, Skylake-U i3-6100U to i7-6600U, 15 W nominal / up to 25 W cTDP brief) — there is no CPU socket and the processor is not replaceable. Optional M.2 WWAN (LTE/HSPA+) bay must be factory-configured with antennas; not a simple drop-in upgrade. Recovery partition reserves ~16–30 GB, so formatted capacity is lower than advertised. Model codes T9F10xx / W5S87xx span many regional SKUs (HD+/FHD, touch, vPro) — check the exact product number before ordering parts.

Upgrade guide → What fits, step by step, and official documents.

2× SO-DIMM DDR4-2133, up to 32 GB: 2 × DDR4 SO-DIMM · up to 32 GB total · 2133 MT/s
1× 2.5" SATA bay + 1× M.2 2280 (SATA/NVMe): 2 × SSD / HDD 2.5" / M.2 2280 (SATA / NVMe) · max 7 mm thick

Slot map

Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

2× SO-DIMM DDR4-2133, up to 32 GB 2 × DDR4 SO-DIMM · up to 32 GB total · 2133 MT/s

Both sockets are user-accessible; nothing is soldered. HP's spec sheet claims 32 GB max, but the Service Guide only formally validates 16 GB modules as 'mobile workstation only' (ZBook 15u G3) — 2×16 GB is widely reported to work, so buy with returns. Update the BIOS before fitting new RAM (HP warns of system problems otherwise). BIOS has no XMP: use plain JEDEC DDR4-2133/2400 CL14 SODIMMs; exotic sub-timings won't boot. Mixed sizes/speeds run single-channel at the slower speed. Single module must go in socket '1'.

No compatible offers right now.

1× 2.5" SATA bay + 1× M.2 2280 (SATA/NVMe) 2 × SSD / HDD 2.5" / M.2 2280 (SATA / NVMe) · max 7 mm thick

2.5" bay takes SATA-3 drives up to 7 mm thick only — HP's Service Guide is explicit; Kingston's 9.5 mm listing is wrong and such drives won't close. All drives use the same bracket/caddy. M.2 2280 slot accepts B+M or M key SATA or NVMe drives, but runs at PCIe 3.0 ×4 max (Gen4 drives work at Gen3 speed; no minimum Gen required). Both bays can be used simultaneously unless the hybrid SSHD option is fitted. No documented capacity limit; HP shipped up to 512 GB M.2 / 1 TB HDD and larger aftermarket drives (2 TB 2.5" 7 mm, 1–2 TB NVMe) are commonly used but not HP-validated.

No compatible offers right now.