HPE ProLiant ML350 Gen12 Memory

Genuine HPE DDR5 Smart Memory for the HPE ProLiant ML350 Gen12, new and refurbished, tested before shipping. The tower carries 32 DIMM slots across two Intel Xeon 6 processors, every listed kit is DDR5-6400, and the two decisions that matter are which capacity you commit to and whether you fill one or two slots per channel.

ML350 Gen12 Memory Specifications

• Type: HPE DDR5 Smart Memory, EC8 Registered (RDIMM); the document lists Registered modules only
• Slots: 32 — 16 per processor, 8 channels per processor, 2 DIMMs per channel; 16 available with a single processor
• Kits listed: 32GB dual-rank x8, 64GB, 96GB and 128GB dual-rank x4 (CAS-52-52-52), and 256GB quad-rank x4 3DS (CAS-60-52-52), all DDR5-6400
• Speed: 6400 MT/s at one DIMM per channel, 5200 MT/s at two; every listed Xeon 6700P/6500P processor supports DDR5-6400
• Maximum capacity: 8.0TB, documented as 32 × 256GB RDIMM at 5200 MT/s at 2 DPC
• Population: 1, 2, 4, 8, 12 or 16 DIMMs per socket; white slots (furthest from the CPU) first, starting at slot 10, then 7, 3 and 14
• Protection: Advanced ECC

Choose one capacity and buy the whole population in it. HPE states that 64GB, 96GB, 128GB and 256GB modules cannot be mixed with any other capacity, and that x4 and x8 modules cannot be mixed — the 32GB kit is the only x8 part. Then decide on speed: one DIMM per channel runs at 6400 MT/s, two per channel drop the whole bank to 5200 MT/s, so sixteen larger modules beat thirty-two smaller ones at the same total.

How much memory can the ML350 Gen12 hold?

The practical sweet spot is sixteen modules at one DIMM per channel: 1TB with 64GB kits or 2TB with 128GB kits, both at the full 6400 MT/s. Filling the second slot in each channel doubles capacity and drops the bank to 5200 MT/s, so 16 × 128GB is the faster route to 2TB than 32 × 64GB.

Choosing the Right ML350 Gen12 Memory

• Pick one capacity per server. HPE states that 64GB, 96GB, 128GB and 256GB modules cannot be mixed with any other capacity. The 32GB kit is the only x8 module and x4 cannot be mixed with x8, so it cannot be combined with a larger kit either.
• One DIMM per channel keeps 6400 MT/s. Size the modules for the capacity you need at 1 DPC before reaching for the second slot.
• Respect the quantities. Per socket, HPE allows 1, 2, 4, 8, 12 or 16 DIMMs, split evenly across both processors and loaded similarly across channels.
• 256GB kits need airflow. A redundant fan configuration — the Redundant Fan Kit fitted with the Second CPU Fan Kit — is required for 256GB memory.
• Order the -B21 SKU. HPE's -B21 memory part numbers are the stand-alone kits; the matching -F21 numbers are factory-integration only. Every kit is a single DIMM.

Complete Your ML350 Gen12 Build

The processor sets the DDR5 ceiling and a second one opens the other 16 slots — see ML350 Gen12 processors before settling on capacity. For the rest of the tower, browse ML350 Gen12 drives, storage controllers, networking adapters and power supplies, or the full ML350 Gen12 parts listing. The adjacent generation is ML350 Gen11 memory, and all DDR5-6400 kits sit under HPE Gen12 server memory. Background reading: maximum memory configurations for HPE ProLiant Gen12 servers, understanding memory rank and why memory speed matters, plus the HPE parts by server model index.

ML350 Gen12 Memory FAQ

How much RAM does the ML350 Gen12 support?
8TB, which HPE documents as 32 x 256GB RDIMMs running at 5200 MT/s with two DIMMs per channel. With one processor installed only 16 of the 32 slots are available, so the single-processor ceiling with the same 256GB modules is sixteen of them, or 4TB.

What type of memory does the ML350 Gen12 use?
HPE DDR5 Smart Memory EC8 Registered DIMMs at DDR5-6400. The QuickSpecs list Registered modules only, in 32GB, 64GB, 96GB, 128GB and 256GB kits, all -B21 stand-alone part numbers.

Can I mix different memory capacities in an ML350 Gen12?
Not in practice. HPE states that 64GB, 96GB, 128GB and 256GB modules cannot be mixed with any other capacity, and that x4 and x8 modules cannot be mixed - the 32GB kit is the only x8 part. Choose one capacity and buy the whole population in it.

Why does my ML350 Gen12 memory run at 5200 instead of 6400 MT/s?
Because a channel has two DIMMs in it. HPE documents 6400 MT/s at one DIMM per channel and 5200 MT/s at two, regardless of which listed Xeon 6 processor is fitted. Sixteen larger modules at 1 DPC keep full speed.

How many memory slots does the ML350 Gen12 have?
32 - sixteen per processor across eight channels with two slots each. Only sixteen are usable until a second processor is installed, and HPE requires 1, 2, 4, 8, 12 or 16 DIMMs per socket.

Do 256GB DIMMs need anything else in the ML350 Gen12?
Yes. HPE requires a redundant fan configuration for 256GB memory, meaning the Redundant Fan Kit fitted together with the Second CPU Fan Kit. The 256GB kit is also quad-rank 3DS with CAS-60 timing, against CAS-52 on the smaller kits.

✅ Looking for a specific ML350 Gen12 memory module? Browse our full selection below.

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