HPE ProLiant DL380a Gen12 Memory

Genuine HPE DDR5 Smart Memory for the HPE ProLiant Compute DL380a Gen12, new and refurbished. The server carries 32 DIMM slots — 16 per processor across 8 memory channels — and takes Registered DIMMs only, so the decisions here are capacity, speed and how many modules the processor family lets you install.

DL380a Gen12 Memory Specifications

• Type: HPE DDR5 Smart Memory, Registered (RDIMM) only; every kit listed is a DDR5-6400 EC8 module
• Slots: 32 in total — 16 per processor, 8 channels per processor, up to 2 DIMMs per channel; at least one DIMM per socket is required
• Kits listed: 16GB single-rank x8, 32GB dual-rank x8, 64GB, 96GB and 128GB dual-rank x4, and 256GB quad-rank x4 3DS
• Maximum capacity: 8.0TB with 32 × 256GB RDIMMs at 5200 MT/s (2DPC), or 4.0TB with 16 × 256GB at 6400 MT/s (1DPC)
• Speed: up to 6400 MT/s at one DIMM per channel, up to 5200 MT/s at two; the processor sets the ceiling — the 6710E and 6746E are 5600 MT/s parts, every other listed Xeon 6 is 6400 MT/s
• Population: total DIMM count must be 4, 8, 16 or 32 with E-core processors, or 4, 8, 16, 24 or 32 with P-core; per processor, 1, 2, 4, 8 and 16 DIMMs on E-core and 1, 2, 4, 8, 12 and 16 on P-core
• Restrictions: rank mixing is not allowed, x4 and x8 DIMMs cannot share a channel or a socket, and the 16GB kit is allowed only in quantities of 4, 8 or 16 and not with E-core processors

Count the DIMMs against the processor family before you count capacity. E-core builds must total 4, 8, 16 or 32 modules and cannot use the 16GB kit at all; P-core builds add 24 as a valid total. Rank mixing is not allowed and x4 and x8 modules cannot share a socket, so an upgrade matches the kit already fitted — and filling the second slot in each channel steps every module from 6400 MT/s down to 5200 MT/s.

How much memory can the DL380a Gen12 hold?

Filling the second slot in each channel steps the transfer rate from 6400 MT/s to 5200 MT/s, so 16 larger modules run faster than 32 smaller ones at the same capacity. HPE's sizing guideline for this platform is system memory of twice the total GPU memory, which on an eight-GPU build points at the 128GB and 256GB kits.

Choosing the Right DL380a Gen12 Memory

• Count DIMMs against the processor family first. E-core builds total 4, 8, 16 or 32 modules; P-core builds add 24. Anything else is not a supported configuration.
• Keep every module identical. No rank mixing, no x4 beside x8 in a channel or socket, one speed per socket — an upgrade matches the kit already fitted or replaces it.
• One DIMM per channel for speed, two for capacity. 6400 MT/s at 1DPC, 5200 MT/s at 2DPC, and only a 6400 MT/s processor reaches the top figure.
• Order the -B21 part number. The -F21 twin is HPE's factory-integration SKU; the -B21 is the standalone kit.
• Balance across both processors. HPE recommends splitting total capacity evenly between the two installed processors.

Complete Your DL380a Gen12 Build

The processor decides the memory ceiling and the valid DIMM counts — see DL380a Gen12 processors first. Also available: DL380a Gen12 drives, storage controllers, networking adapters and power supplies, or the full DL380a Gen12 parts listing. The two-socket sibling is DL380 Gen12 memory; all Gen12 kits are under HPE Gen12 server memory. Background reading: maximum memory configurations for HPE ProLiant Gen12 servers, understanding memory rank, the importance of memory speed and the HPE parts by server model index.

DL380a Gen12 Memory FAQ

How much RAM does the DL380a Gen12 support?
8.0TB, using 32 x 256GB DDR5 RDIMMs at 5200 MT/s with two DIMMs per channel. With one DIMM per channel the documented maximum is 4.0TB from 16 x 256GB at 6400 MT/s. Kits are listed from 16GB to 256GB.

What type of memory does the DL380a Gen12 use?
HPE DDR5 Smart Memory Registered DIMMs (RDIMM) only. Every kit listed for the server is a DDR5-6400 EC8 module, from single-rank x8 16GB to quad-rank x4 256GB 3DS, and HPE states that only DDR5 DIMMs are allowed.

What is the maximum memory speed of the DL380a Gen12?
6400 MT/s with one DIMM per channel and up to 5200 MT/s with two, depending on the memory and processor selected. The processor sets the ceiling: the Xeon 6710E and 6746E are 5600 MT/s parts, every other listed Xeon 6 supports 6400 MT/s.

How many DIMMs do I have to install in a DL380a Gen12?
A total of 4, 8, 16 or 32 with 6700-series E-core processors, or 4, 8, 16, 24 or 32 with P-core processors, with at least one DIMM per socket. Per processor HPE allows 1, 2, 4, 8 and 16 DIMMs on E-core and 1, 2, 4, 8, 12 and 16 on P-core.

Can I mix memory kits in a DL380a Gen12?
Not across ranks or widths. HPE states that rank mixing is not allowed, that x4 and x8 DIMMs cannot be mixed in the same channel or processor socket, and that all DIMMs on a socket must run at the same speed. Match the kit already installed.

Can I use the 16GB DIMM in a DL380a Gen12?
Only with P-core processors, and only in quantities of 4, 8 or 16. HPE lists the 16GB kit as not supported with Intel Xeon 6700-series E-core processors.

What is the difference between the -B21 and -F21 memory part numbers?
The -B21 SKU is the standalone memory kit, which is what you order to add or replace memory. HPE's -F21 SKU for the same module is the factory-integration version used when a server is configured with memory installed at build time.

✅ Looking for a specific DL380a Gen12 memory module? Browse our full selection below.

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