HPE ProLiant DL380 Gen10 memory compatibility & population rules

The DL380 Gen10 is flexible about capacity but strict about DIMM type, speed rating, and slot order. This guide lays out the platform's DDR4 rules — checked against HPE QuickSpecs and HPE's Gen10 memory population white paper — so a memory upgrade posts at full speed on the first boot.

DL380 Gen10 Memory Architecture at a Glance

The HPE ProLiant DL380 Gen10 is a two-socket platform built on the Intel Xeon Scalable family (1st and 2nd generation). Each processor carries two integrated memory controllers driving six DDR4 channels, with two DIMM slots per channel — 12 slots per CPU, 24 total. All 24 slots are usable only with both processors installed; with a single CPU, only its 12 slots are active.

Note that the CPU itself caps addressable memory per socket. Standard 2nd-gen Xeon Scalable SKUs address up to 1 TB per socket; M-suffix SKUs raise that to 2 TB. Reaching the platform's 3.0 TB LRDIMM maximum therefore requires higher-memory-tier (M/L-class) processors, not the base SKUs.

Memory Speed by Processor Generation

DL380 Gen10 memory speed is set by the processor, not the motherboard. Per HPE QuickSpecs, DDR4-2666 kits are supported with 1st-generation Xeon Scalable processors and DDR4-2933 kits with 2nd-generation processors — and within each generation, lower processor tiers clock memory down further. All DIMMs on a CPU run at the highest speed common to every installed module and the processor.

Practical takeaway: pairing DDR4-2933 kits with a Silver 4210 yields 2400 MT/s operation — the memory works, but you paid for headroom the CPU cannot use. Match the kit speed to the processor tier actually installed.

Supported DIMM Types — and What You Cannot Mix

The platform accepts two DDR4 module classes: RDIMMs (8, 16, 32, and 64 GB) and LRDIMMs (64 and 128 GB). Unbuffered DIMMs are not supported at all. HPE's population white paper states the mixing rules plainly:

• Never mix RDIMMs and LRDIMMs in the same system. This is a hard rule — the server will not run a mixed configuration.
• Do not mix 128 GB LRDIMMs with other capacity DIMMs.
• DIMMs of different rated speeds may be mixed; the system clocks all memory to the slowest common speed.
• x4 and x8 DIMMs may share a channel, but mixing them affects RAS features (Online Spare, Mirrored Memory, HPE Fast Fault Tolerance).
• HPE memory carried over from Gen9 or earlier servers is not compatible with Gen10.

For most refurbished DL380 Gen10 builds, dual-rank x4 RDIMMs are the sweet spot of price, capacity, and RAS support; LRDIMMs only earn their premium above roughly 1.5 TB per system. See our RDIMM vs LRDIMM guide for the buffering trade-offs in detail.

Population Order: Which Slots, in Which Order

HPE's rule set is consistent across Gen10 12-slot-per-CPU servers: populate white slots first (the first slot of each channel, farthest from the CPU), keep channels balanced, and split DIMMs evenly across both processors. When ranks differ within a channel, the DIMM with the most ranks goes in the white slot. The table below reproduces HPE's published population order per processor.

Three DIMMs per CPU (slots 8, 10, 12) is also a valid balanced option. Counts of 5, 7, 9, 10, or 11 DIMMs per CPU are flagged by HPE as unbalanced and not recommended: the memory controller splits an unbalanced population into multiple interleave regions, and throughput in the smaller region can fall to a third of the balanced figure. In a two-CPU server, install identical sets on each processor — 12 DIMMs total should be 6 + 6, never 8 + 4.

HPE SmartMemory vs. Third-Party DIMMs

HPE SmartMemory Gen10 kits are standard JEDEC DDR4 modules that carry HPE authentication data. The server recognizes authenticated modules and enables platform features on top of base ECC: integration with the HPE Active Health System for memory-event diagnostics, and HPE Fast Fault Tolerance, which HPE specifies as requiring SmartMemory in x4 organization. Third-party JEDEC-compliant DIMMs will generally POST and run, but without those HPE-specific features.

The reference part for 2nd-gen builds is P00924-B21, the HPE 32GB 2Rx4 PC4-2933Y-R Smart Kit: dual-rank x4, CL21, 1.2 V ECC RDIMM, qualified across the DL360/DL380/DL560/DL580 Gen10 family. Twelve of them fill one CPU's channels at 2 DPC for 384 GB per socket; twenty-four give a balanced 768 GB system. Per HPE QuickSpecs, DDR4-2933 kits like this one are supported only with 2nd-generation Xeon Scalable processors — 1st-gen systems should use the 2666 equivalents (for example, 815100-B21 in 32 GB).

All genuine HPE kits in our memory catalog are pulled, tested, and matched by part number, so the authentication and feature set behave exactly as factory-shipped memory.

Buying Checklist for a Refurbished DL380 Gen10 Upgrade

Before ordering, confirm five things:

• CPU generation. Check the processor model in iLO. 62xx/82xx/52xx/42xx/32xx means 2nd gen and 2933-class kits; 61xx/81xx/51xx/41xx/31xx means 1st gen and 2666-class kits.
• Existing DIMM type. If the chassis already has RDIMMs, buy RDIMMs — never add LRDIMMs to an RDIMM system or vice versa.
• Rank and organization. Match existing modules where possible (e.g., 2Rx4); required if you plan to use mirroring or Fast Fault Tolerance.
• Target count per CPU. Aim for 4, 6, 8, or 12 per processor, identical on both sockets.
• Per-socket capacity ceiling. Standard SKUs top out at 1 TB per socket on 2nd gen; very large configs need M/L-class processors.

If you would rather not cross-check part numbers by hand, run your server's model and CPU through our compatibility tool and it will return only qualified kits.

Last verified 16 July 2026 against HPE’s DL380 Gen10 QuickSpecs and memory population guidelines.

Related reading: Dell PowerEdge R740 supported CPUs and RDIMM vs LRDIMM: which buffer type fits your workload.

Frequently asked questions

What is the maximum memory for the DL380 Gen10?

1.5 TB using twenty-four 64 GB RDIMMs, or 3.0 TB using twenty-four 128 GB LRDIMMs. The processor must also support the per-socket total: standard 2nd-gen Xeon Scalable SKUs address up to 1 TB per socket, so the 3.0 TB configuration requires higher-memory M/L-class CPU SKUs.

Can I mix RDIMMs and LRDIMMs in a DL380 Gen10?

No. HPE's Gen10 population rules prohibit mixing RDIMMs and LRDIMMs in the same system, and additionally prohibit mixing 128 GB LRDIMMs with any other capacity. Choose one module class for the entire server.

Will DDR4-2933 kits like P00924-B21 work with 1st-gen Xeon Scalable CPUs?

HPE's QuickSpecs support matrix pairs DDR4-2933 kits only with 2nd-generation Xeon Scalable processors and DDR4-2666 kits only with 1st-generation processors. On a 1st-gen DL380 Gen10 (Xeon 41xx/51xx/61xx/81xx), use 2666-rated kits such as 815100-B21 instead of P00924-B21.

How many DIMM slots does the DL380 Gen10 have, and which do I fill first?

24 slots — 12 per processor, arranged as six channels with two slots each. Fill white slots first (the first slot of each channel): slot 8 for one DIMM, 8 and 10 for two, 3/5/8/10 for four, and 1/3/5/8/10/12 for six per CPU. Split DIMMs evenly across both processors.

Do I have to use HPE-branded memory in a DL380 Gen10?

No — JEDEC-compliant third-party DDR4 RDIMMs/LRDIMMs of the correct speed and type will generally work. However, HPE-specific features such as Fast Fault Tolerance and Active Health System memory diagnostics require authenticated HPE SmartMemory, which is why matched genuine HPE kits are the safer choice for production systems.

Can I install DIMMs of different capacities together?

Yes, within limits. HPE permits mixing capacities and speeds (everything clocks to the slowest common speed), provided you keep channels balanced and place the DIMM with the highest rank count in the white slot of each channel. The exception is 128 GB LRDIMMs, which cannot be mixed with any other capacity.