HPE ProLiant ML350 Gen11 Upgrade Guide: RAM and Storage

Updated Oct. 9, 2026 · Written from this device's verified specifications

This guide covers memory and drive upgrades for the HPE ProLiant ML350 Gen11. The short answer: buy registered DDR5 ECC RDIMMs for memory, and match drives to the bay type and controller your chassis has.

At a glance

  • Up to 32 DDR5 RDIMM slots (16 per CPU), 256 GB largest module, 8 TB maximum
  • Memory runs at DDR5-4800 with 4th Gen Xeon and DDR5-5600 with 5th Gen Xeon
  • The chassis is ordered as 12 LFF 3.5 inch, up to 24 SFF 2.5 inch, or 12 EDSFF bays
  • No drives come as standard, and you need a storage controller or the embedded SATA (VROC)
  • UDIMMs and 6400 MT/s memory are unconfirmed, so stick to RDIMMs
DDR5 RDIMM slots32 × DDR5 DIMM · up to 8.192 TB total · 5600 MT/s · registered (RDIMM) · ECC
LFF 3.5" drive bays (12-bay chassis)12 × HDD / SSD 3.5" (SATA / SAS)
SFF 2.5" drive bays (up to 24)24 × HDD / SSD 2.5" (SAS / SATA / NVMe)
32 × DIMM · DDR5up to 8 TB totalLFF 3.5" drive bays (12-bay chassis)12 × HDD / SSD 3.5" (SATA / SAS)SFF 2.5" drive bays (up to 24)24 × HDD / SSD 2.5" (SAS / SATA / NVMe)
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.

20232024202520262027Today11 · Release · Jan. 10, 2023
Filled dots: dates published by the manufacturer. Hollow dots: estimates from third-party sources.
MilestoneDate
Release
First available to buy.		 Jan. 10, 2023 Estimate Third-party date from eosl.date, inferred from an unlabeled table column; no HPE launch announcement found.
Source ↗

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

Memory (RAM): DDR5 registered ECC DIMMs

The ML350 Gen11 has 32 DIMM slots in a dual-CPU system: 16 per processor, with 8 channels per processor and 2 DIMMs per channel. It uses full-size DDR5 registered DIMMs (RDIMMs) with ECC, not SO-DIMMs. No soldered memory is mentioned, so all memory sits in the DIMM slots.

HPE lists these module sizes, each at 4800 and 5600 MT/s: 16 GB (1Rx8), 32 GB (2Rx8), 64 GB (2Rx4), 96 GB (2Rx4), 128 GB (2Rx4 or 4Rx4) and 256 GB (8Rx4). Filling all 32 slots with 256 GB modules gives the 8 TB maximum.

Speed depends on the CPU. 4th Gen Intel Xeon Scalable processors run DDR5-4800 and 5th Gen processors run DDR5-5600. The full 8 TB setup (256 GB modules, 2 DIMMs per channel) drops to 4400 MT/s with either generation. HPE says real speed depends on memory type, configuration and processor model, so check HPE's memory population rules before ordering.

The 32 slots need two CPUs. A single-CPU machine most likely has only 16 usable slots, which would mean a 4 TB ceiling. That is our reading of the slot split, not a figure HPE states.

Buying tips

  • Buy DDR5 RDIMMs only, at 4800 or 5600 MT/s to match your CPU generation.
  • Don't buy UDIMMs or 6400 MT/s modules. Support for them is not confirmed.
  • HPE's documents list only HPE Smart Memory part numbers. Third-party module compatibility isn't addressed, so check before using non-HPE modules.
  • Check how many CPUs your server has before planning for more than 16 slots.

Storage: 3.5 inch and 2.5 inch drive bays

The server ships with no hard drive or SSD as standard. The chassis is ordered as 12 LFF (3.5 inch), up to 24 SFF (2.5 inch), or 12 EDSFF bays, so check which one you have. LFF bays take SATA or SAS drives. SFF bays take SAS, SATA or NVMe. You need a storage controller or the embedded SATA (Intel VROC) to use drives.

HPE's listed maximums are 12 x 20 TB LFF HDDs, 12 x 960 GB LFF SSDs, 24 x 2.4 TB SFF SAS HDDs, 24 x 15.36 TB SFF SAS SSDs, 24 x 7.68 TB SFF SATA SSDs, 24 x 15.36 TB SFF NVMe SSDs, and 12 x 15.3 TB EDSFF NVMe SSDs. Embedded SATA supports up to 12 LFF drives or 8 SFF drives. With the optional HPE NS204i-u boot device (2 x 480 GB M.2 NVMe in RAID 1), it supports up to 8 LFF or 8 SFF bays.

NVMe needs either a tri-mode controller or VROC NVMe. VROC NVMe is direct-attach for up to 8 x4 bays, NVMe SSDs only, and a license is needed for RAID. Controller options include the Smart Array E208e-p SR Gen10 and the tri-mode MR216i-o, MR216i-p, MR408i-o, MR416i-o, MR416i-p and SR932i-p.

Also know that VROC works in UEFI mode only (legacy boot needs an additional controller) and SATA VROC is off by default. NVMe VROC is not supported on the 4510, 4509Y and 3508U CPUs. HPE's documents don't state drive thickness limits, the M.2 lengths, or the NS204i-u PCIe generation, so we can't confirm those.

Buying tips

  • Match the drive to your bay type first: 3.5 inch for LFF chassis, 2.5 inch for SFF chassis.
  • For NVMe, confirm you have a tri-mode controller or VROC, and budget for the RAID license if you want NVMe RAID.
  • Check the product data sheet or user guide before buying M.2 boot drives, since lengths aren't confirmed.
  • Drive thickness limits aren't documented, so confirm before buying thick enterprise 2.5 inch drives.

Cheapest compatible right now

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How to upgrade

Before you start

  • Check how many CPUs are installed, since that sets how many memory slots you can use.
  • Check your chassis bay type (LFF, SFF or EDSFF) and which storage controller you have.
  • Back up your data and note your current RAID setup.
  • Update the server firmware and BIOS if the owner's manual or HPE recommends it for the part you are adding.
  • Have the owner's manual or service guide open for exact disassembly steps.

Steps

  1. Back up your data
    Make a full backup and note any RAID configuration before touching hardware.
  2. Power off and unplug
    Shut the server down fully and disconnect all power cables and peripherals.
  3. Ground yourself
    Use an anti-static wrist strap or touch bare metal on the chassis before handling parts, and hold modules and drives by their edges.
  4. Open the case
    Follow the owner's manual or service guide to open the server and reach the memory slots or drive bays. Details such as latches and screws vary, so use HPE's guide.
  5. Install the part
    For memory, follow HPE's memory population rules for slot order. For drives, fit them in the correct bay type and connect through your controller or the embedded SATA. Follow the manual for how bays are released and populated.
  6. Close and reconnect
    Put covers back as the manual describes, then reconnect power and start the server.
  7. Check that it sees the part
    Open the BIOS or firmware setup and confirm the new memory total or drive appears. For VROC, remember it needs UEFI mode and SATA VROC is off by default. Set up RAID if you need it.

Good to know

  • This guide covers memory and storage only. CPU upgrade details aren't covered here. The server takes 4th and 5th Gen Intel Xeon Scalable processors. CPUs rated 300 W or more need both the Redundant Fan Kit (P47219-B21) and the Second CPU Fan Kit (P47902-B21). Secondary and tertiary riser slots depend on a second CPU.
  • M.2 lengths, the NS204i-u PCIe generation, EDSFF form-factor details and drive thickness limits could not be confirmed.
  • UDIMM and 6400 MT/s support are unconfirmed, and third-party memory and drive compatibility isn't addressed.
  • The 16-slot, 4 TB single-CPU figure is our inference, not an HPE specification.
  • Some manuals come from Hitachi's HA8000V Gen11 rebrand of this server and may differ in wording or version from HPE's own documents.
  • Actual memory speed varies with memory type, configuration and processor model.

Frequently asked questions

How much RAM can the HPE ProLiant ML350 Gen11 take?

Up to 8 TB: 32 slots of 256 GB DDR5 RDIMMs, which needs two CPUs. A single-CPU system probably has only 16 usable slots, so likely 4 TB, though HPE doesn't state that figure.

What type of memory does the ML350 Gen11 use?

DDR5 registered ECC DIMMs (RDIMMs) in full-size DIMM slots. Speed is DDR5-4800 with 4th Gen Xeon and DDR5-5600 with 5th Gen Xeon.

Does the ML350 Gen11 support UDIMMs or 6400 MT/s memory?

We couldn't confirm it. HPE's specifications list only RDIMMs at 4800 and 5600 MT/s, although one user guide's module label decoder mentions UDIMM and 6400. Buy RDIMMs.

Does the ML350 Gen11 support NVMe SSDs?

Yes, in the 2.5 inch bays, with a tri-mode controller or VROC NVMe (up to 8 direct-attach x4 bays, license needed for RAID). There is also a 12-bay EDSFF NVMe chassis option.

What is the biggest drive I can fit?

HPE lists 20 TB for LFF HDDs and 960 GB for LFF SSDs. For SFF, it lists 15.36 TB SAS and NVMe SSDs, 7.68 TB SATA SSDs and 2.4 TB SAS HDDs.

Does the server come with drives?

No. No HDD or SSD is included as standard, and you need a storage controller or the embedded SATA (VROC) to use drives.

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.