HPE ProLiant Gen11 Memory: DDR5 Part Numbers for DL360 & DL380
HPE ProLiant Gen11 (DL360/DL380 Gen11) uses DDR5-4800 ECC RDIMM only — no DDR4, no UDIMM (the slots are physically keyed for DDR5). The common HPE Smart Memory part numbers are P43328-B21 (32GB), P43331-B21 (64GB), and P43334-B21 (128GB). Here are the compatibility rules, population tips, and how to save with tested modules.
TL;DR — Direct Answer
HPE ProLiant Gen11 servers (DL360 Gen11, DL380 Gen11, and siblings) use DDR5-4800 ECC RDIMM memory — and only that. You cannot use DDR4, and you cannot use desktop/UDIMM modules: DDR5 has a different physical key, so older DIMMs will not seat.
The common HPE Smart Memory Gen11 part numbers:
| Capacity | HPE Part Number | Type |
|---|---|---|
| 32 GB | P43328-B21 | DDR5-4800 RDIMM (2Rx8) |
| 64 GB | P43331-B21 | DDR5-4800 RDIMM (2Rx4) |
| 128 GB | P43334-B21 | DDR5-4800 RDIMM (2Rx4) |
For very high per-DIMM capacity, Gen11 also supports DDR5 LRDIMM — but for most builds, RDIMM is the right choice. Always confirm the exact PN against the HPE QuickSpecs for your model. Below are the rules that keep your config running at full speed.
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Why Gen11 is DDR5-only
Gen11 moved to 4th/5th-Gen Intel Xeon Scalable (and AMD EPYC on some models), which dropped DDR4 support entirely. DDR5 brings higher bandwidth, on-die ECC, and per-module power management — but it is not backward compatible. The notch position on a DDR5 DIMM is different from DDR4, so a DDR4 stick physically will not fit a Gen11 slot. If you are coming from a Gen10/Gen10 Plus, your old memory does not carry over.
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Population rules (so you don't lose speed)
DDR5 server memory is sensitive to how you populate channels:
- Balance across channels and CPUs. Fill the same number of DIMMs per channel on each populated CPU. Lopsided configs run slower or won't post.
- One DIMM per channel generally runs at the rated 4800 MT/s; two DIMMs per channel may step down depending on platform and module rank.
- Don't mix RDIMM and LRDIMM, and avoid mixing ranks/capacities within a channel where possible.
- Use HPE Smart Memory (the P-series PNs) for full iLO reporting and validated timings.
The DL380 Gen11 service guide and HPE QuickSpecs publish the exact DIMM-slot population order — follow it for your CPU count.
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New vs tested/refurbished memory
DDR5 server memory is expensive right now (an AI-driven supply crunch has pushed server DRAM prices up sharply through 2026). Memory has no moving parts and effectively no wear, which makes tested/pulled DDR5 RDIMMs one of the lowest-risk ways to cut a Gen11 build cost — often 30-50% below new — with the same HPE part number and a warranty. For a 12- or 24-DIMM DL380 Gen11, that adds up fast.
See our Server RAM Buying Guide: DDR4 vs DDR5 ECC for the deeper RDIMM/LRDIMM and speed-tier discussion.
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Frequently Asked Questions
Does HPE ProLiant Gen11 use DDR4 or DDR5?
DDR5 only — specifically DDR5-4800 ECC RDIMM. DDR4 will not physically fit (DDR5 is keyed differently), so Gen10/Gen10 Plus memory does not carry over to Gen11.
What memory does a DL380 Gen11 take?
DDR5-4800 ECC RDIMM (and LRDIMM for high capacity). Common HPE Smart Memory PNs are P43328-B21 (32GB), P43331-B21 (64GB), and P43334-B21 (128GB). Confirm the exact PN in the HPE QuickSpecs for your CPU.
Can I mix different HPE memory part numbers in a Gen11?
Keep it balanced — same type (RDIMM), and ideally matching rank/capacity within a channel. Mixing RDIMM and LRDIMM is not supported, and unbalanced configs reduce speed or fail to post.
Is refurbished/tested DDR5 server memory reliable?
Yes — memory has no mechanical wear, and tested modules carrying the correct HPE PN perform identically to new. With DDR5 prices elevated, it's a common, low-risk way to save on a Gen11 build.
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Where to buy
Pro Disk Network stocks HPE ProLiant server memory — DDR5 Gen11 RDIMM/LRDIMM and DDR4 for Gen10/earlier — new and tested, with HPE part numbers and a warranty, same-day US shipping, and Net 30 for verified businesses. Tell us your model and target capacity and we'll spec a balanced, full-speed config. Contact us.
Related: HP ProLiant DL380 Gen11 vs Gen10 Plus vs Gen10 · Cisco & HPE End-of-Life Guide