HP Inc. HP Z4 G4 Tower Workstation upgrades

Released 2017 · on sale

Workstation is discontinued (HP Japan sales ended 2023-07-20). Two effectively different platforms ship under this name (C422 + Xeon W vs X299 + Core X), which determines supported RAM type, CPU family and the number of M.2 slots.

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

8x DDR4 DIMM (ECC RDIMM Xeon / non-ECC UDIMM Core X): 8 × DDR4 DIMM · up to 256 GB total · 2666 MT/s
3.5"/5.25" bays, 6x SATA, 1-2x M.2 NVMe (2.5" adapter): 2 × SSD / HDD 2.5" / 3.5" / M.2 2260 / M.2 2280 / M.2 22110 (SATA / NVMe / SAS)
Intel LGA2066 R4, 1 socket (C422 / X299): LGA3647 / LGA4189 / LGA4677 · Xeon E-2100/2200, Xeon E-2100/2200, Core 8th gen, Core 9th gen · max 165 W

Slot map

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

8x DDR4 DIMM (ECC RDIMM Xeon / non-ECC UDIMM Core X) 8 × DDR4 DIMM · up to 256 GB total · 2666 MT/s

Xeon W (C422) boards take only registered ECC RDIMMs; Core X (X299) boards only non-ECC UDIMMs - wrong type won't POST. 32 GB RDIMMs need the HP memory cooling solution (1MY90AV/1XM34AA). Speed is CPU-bound (W-2102/W-2104 = 2400 MT/s). HP validates 256 GB max (8x32 GB), not the 512 GB in the CPU spec line.

No compatible offers right now.

3.5"/5.25" bays, 6x SATA, 1-2x M.2 NVMe (2.5" adapter) 2 × SSD / HDD 2.5" / 3.5" / M.2 2260 / M.2 2280 / M.2 22110 (SATA / NVMe / SAS)

No native 2.5" bays - brackets/carriers needed. 2nd M.2 exists only on Xeon configs (Core X gets 1). M.2 lengths listed as 2260/2280/22110 but also 'up to 80 mm' - verify the 22110 standoff before buying 110 mm drives. SAS needs a Xeon config plus an add-in SAS controller. 3rd/4th 3.5" drives consume both 5.25" bays (2:1 carrier for 2.5"). No documented drive-size cap; HP options top out at 6 TB HDD / 2 TB SSD.

No compatible offers right now.

Intel LGA2066 R4, 1 socket (C422 / X299) LGA3647 / LGA4189 / LGA4677 · Xeon E-2100/2200, Xeon E-2100/2200, Core 8th gen, Core 9th gen · max 165 W

Form factor value above is a placeholder mapping: the actual socket is Intel LGA2066 R4. Chipset variant decides the CPU family: C422 runs Xeon W-2100 (Skylake-W), X299 runs Core X-series (Skylake-X / Cascade Lake-X) - they are not cross-compatible. HP JP lists later configs with Xeon W-2200 (up to 10 cores); verify board/BIOS revision before buying. Max TDP 140 W (Xeon) / 165 W (Core X).

No compatible offers right now.