HP EliteDesk 800 G3 Small Form Factor upgrade guide

Updated Oct. 11, 2026 · Written from this device's verified specifications

The HP EliteDesk 800 G3 Small Form Factor PC is one of the friendlier business desktops to upgrade: four memory slots, room for an NVMe drive plus several SATA drives, and a socketed CPU you can actually replace. This guide covers what fits, what the limits are, and what to watch out for before you buy. One warning up front: the EliteDesk 800 G3 family includes Desktop Mini and All-in-One variants. Those use small SO-DIMM memory and max out at 32 GB. This page is about the Small Form Factor (SFF) box only, which takes full-size memory and up to 64 GB. Check your machine is the SFF before ordering parts.

At a glance

    4x 288-pin DDR4 UDIMM, 64 GB max (SFF)4 × DDR4 DIMM · up to 64 GB total · 2400 MT/s
    1x M.2 NVMe + 4 SATA bays (2.5/3.5/optical)4 × M.2 2230 / M.2 2280 / 2.5" / 3.5" (NVMe / SATA)
    LGA1151 socket, 6th/7th-gen Intel CoreLGA1151 (6th/7th gen) · Core 6th gen, Core 7th gen · max 65 W
    CPU · LGA1151max 65 W4 × DIMM · DDR4up to 64 GB total1x M.2 NVMe + 4 SATA bays(2.5/3.5/optical)4 × M.2 2230 / M.2 2280 / 2.5" /3.5" (NVMe / SATA)
    Schematic of the upgradeable slots (not to scale). Check the owner's manual for their exact positions.

    Lifecycle and support

    Standard support has ended; paid extended support runs until Oct. 31, 2027.

    201720182019202020212022202320242025202620272028Today11 · Release · January 201722 · End of sale · August 201933 · EOSL · March 31, 202144 · EOL · Oct. 31, 202355 · Extended support ends · Oct. 31, 2027
    Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
    MilestoneDate
    Release
    First available to buy.    		 January 2017 Estimate HP business notebooks, desktops, and workstations - January 2017 product introductions
    Source ↗
    End of sale
    No longer sold new by the manufacturer (Dell calls this 'End of Life', Lenovo 'Withdrawn').    		 August 2019 Estimate HP EliteDesk 800 G3 released in 2017 and discontinued in 2019.
    Source ↗
    End of standard support (EOSL)
    Standard warranty and support contracts can no longer be renewed.    		 March 31, 2021 Official Standard commercial warranty and service options end for product (End of Standard Commercial Warranty and Service).
    Source ↗
    End of life (EOL)
    The manufacturer stops developing the product: no new BIOS, firmware or driver releases.    		 Oct. 31, 2023 Official End of interactive troubleshooting and driver updates; Start of self-help support only (HP Support Assistant), closing of support cases and clear down of support phone lines.
    Source ↗
    End of extended support
    Paid extended support ends; after this there is no manufacturer support at all.    		 Oct. 31, 2027 Official End of Support-Product no longer supported by HP (End of Support).
    Source ↗

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

    Memory (RAM)

    The SFF has four full-size 288-pin DDR4 DIMM slots, two per channel, with nothing soldered to the board. Maximum is 16 GB per module, 64 GB in total.

    What fits: unbuffered, non-ECC DDR4 UDIMMs with proper JEDEC SPD data, rated CL17 at 1.2 V. HP specifies PC4-19200 (DDR4-2400) as the top speed. Modules with x8 or x16 memory chips are fine; x4-based modules are not supported, and XMP-only enthusiast sticks (which don't carry standard JEDEC profiles) can fail to POST. ECC, registered and load-reduced memory is not supported at all. Single- and double-sided modules both work.

    Speed limit depends on the processor. DDR4-2400 needs a 7th-generation CPU; with a 6th-generation chip the memory controller tops out at DDR4-2133. Slower sticks will simply run at the lower speed, and faster sticks usually clock down, but check the profile they carry.

    Buying tips: buy matched pairs so both channels work together. Choose plain JEDEC-spec DDR4-2400 (or 2133) UDIMMs rather than gaming memory. If a stick only advertises XMP timings, skip it — HP warns the system may not work properly with unsupported modules.

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    Storage

    You get two kinds of expansion here: one M.2 NVMe slot and four SATA ports.

    The M.2 slot is an M-key slot for an NVMe drive (HP calls it a Turbo Drive), wired for PCIe 3.0 x4 and sized 2280 (80 mm). HP's own factory drives went up to 1 TB. SATA-protocol M.2 SSDs are not the right purchase here — this slot is documented as PCIe/NVMe only.

    On the 2230 question, HP's documents don't fully agree: the support page shows a fixed 2280 storage slot, while the QuickSpecs describe a 2280/2230 combo socket on some G3 variants. The practical answer is to look at the board before buying — if the standoff is in a second position, a 2230 drive will fit. Don't order a 2280-only heatsink assuming anything.

    The four SATA ports feed two 3.5-inch bays, one 2.5-inch bay and the 9 mm slim optical drive bay. 2.5-inch drives need a bracket or caddy. HP lists factory drives up to 2 TB in 3.5-inch form. There is no published thickness limit, so plan around ordinary desktop hard drives for the 3.5-inch bays and standard 2.5-inch SSD heights. The front SD card slot is a card reader, not an expansion bay.

    The optical bay is the easiest home for an extra SSD: it's 9 mm slim, and third-party caddies let you drop a 2.5-inch drive in. That's not an officially specified storage bay, so treat it as a common mod rather than a documented feature.

    On capacity, HP's documented options stop at 2 TB (HDD) and 1 TB (NVMe), but nothing in the stated spec caps you there. Larger drives are widely used; that simply goes beyond what HP has published.

    Buying tips: one NVMe drive for the operating system and your fastest work, plus cheap SATA SSDs or a big hard drive for bulk storage. If you plan to boot from a new NVMe drive, update the BIOS first. There's a separate M.2 2230 slot on the board for Wi-Fi/Bluetooth — it is not a storage slot, so don't put a drive in it.

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    Processor

    The CPU sits in a standard LGA1151 socket with a normal cooler mount, so it is replaceable. It accepts 6th-generation (Skylake) and 7th-generation (Kaby Lake) Intel Core, Pentium and Celeron processors only.

    The trap: 8th- and 9th-generation chips also use the LGA1151 socket, but they will not work in this machine — the chipset and management engine are different. Ignore socket compatibility alone.

    HP validated the standard 65 W desktop parts. The list includes the i7-7700, i5-7500/7600, i3-7100/7300/7320, Pentium G4560/G4600/G4620, Celeron G3930/G3950, and on the 6th-generation side the i7-6700, i5-6500/6600 and i3-6100. Low-power 35 W T-series parts (such as the i7-7700T) also appear in listings and are a legitimate build-to-order option. Some third-party listings mention 91 W 'K' chips; those are unverified — HP never validated the BIOS, cooler or power supply for them, so don't count on one.

    Practical ceiling: the i7-7700 is the end of the road for this box. The cooler and power supply are sized for 65 W, so sticking within the validated range keeps things quiet and safe.

    Don't forget the memory tie-in above: a 6th-generation CPU limits you to DDR4-2133. If you want the full 2400 MT/s, go 7th-gen.

    Buying tips: a used i7-7700 or an i5-7500/7600 is usually the sensible move. If you upgrade the CPU at the same time as the memory, match the generation so you don't waste speed.

    How to upgrade

    Before you start

    • Back up anything you care about before opening the case.
    • Shut the PC down properly and unplug the power cable (and anything else attached).
    • Ground yourself — touch the metal chassis or use an anti-static wrist strap — before handling components.
    • Open the case. HP's Maintenance and Service Guide shows the exact disassembly steps and which screws and latches to release; use that rather than guessing.
    • Fit the part: seat memory modules firmly until the side clips lock, screw an M.2 drive down at the standoff, and for a CPU follow the socket's marked orientation and refit the cooler.
    • Close the case, reconnect the power and switch on.
    • Check that the BIOS/firmware sees the new part (memory total, drive listed, CPU model) before you boot into your operating system. For a new NVMe boot drive, updating the BIOS first is the smoother path.

    Good to know

    • Don't confuse the SFF with the Desktop Mini or All-in-One versions of the EliteDesk 800 G3 — different memory slots and a lower maximum.
    • Beyond HP's documented options (2 TB HDD, 1 GB... 1 TB NVMe) larger drives are common in practice but fall outside HP's published spec.
    • This machine ships with TPM 2.0 (downgradeable to TPM 1.2), but its 6th/7th-generation processors are outside Microsoft's official Windows 11 CPU list — check OS compatibility separately if that matters to you.

    Frequently asked questions

    How much RAM can the HP EliteDesk 800 G3 SFF take?

    Up to 64 GB — four slots, 16 GB per module. That figure is for the SFF and Tower; the Desktop Mini and All-in-One versions of the same family only take 32 GB.

    What RAM do I need for the EliteDesk 800 G3?

    288-pin DDR4 UDIMMs, unbuffered and non-ECC, with standard JEDEC profiles (CL17 at 1.2 V). ECC, registered, x4-based and XMP-only modules are not supported and may not POST. Use matched pairs for dual-channel.

    Does it support NVMe SSDs?

    Yes. There is one M.2 M-key slot for an NVMe PCIe 3.0 x4 drive (HP's Turbo Drive), in 2280 size — some boards also accept 2230, so check your standoff. The slot is NVMe only; a SATA M.2 SSD is not the right fit. The remaining drive bays are SATA.

    Which CPUs fit the EliteDesk 800 G3 SFF?

    6th- and 7th-generation Intel Core, Pentium and Celeron processors on LGA1151, in the 65 W class validated by HP (the i7-7700 is the practical top). 8th/9th-gen chips share the socket but won't work. Low-power 35 W T-series parts also fit; 91 W 'K' chips are unverified for this machine.

    Can I add a graphics card?

    A modest one. The PCIe slots take low-profile cards up to about 6.6 inches long, and the x16 slots are rated 35 W with no auxiliary power connector — so no gaming card. Low-profile, low-power cards are the realistic option. HP's own discrete option was a GeForce GT 730 2 GB.

    Will faster RAM run at its rated speed?

    Only within the machine's limits: DDR4-2400 is the documented maximum, and that requires a 7th-generation CPU. A 6th-generation CPU caps memory at DDR4-2133. Faster modules generally clock down to match.

    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.