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 ECC RDIMM memory (up to 4800 MT/s with 4th Gen Xeon, up to 5600 MT/s with 5th Gen Xeon) — 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 3DS RDIMM (4Rx4) |
For very high per-DIMM capacity, Gen11 uses 3DS RDIMMs such as the 128 GB P43334-B21. 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.
- 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 pulled DDR5 RDIMMs one of the lowest-risk ways to cut a Gen11 build cost, 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 ECC RDIMM (4800 MT/s with 4th Gen Xeon, up to 5600 MT/s with 5th Gen Xeon). 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 ECC RDIMM (including 3DS RDIMM 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. Unbalanced configs reduce speed or fail to post.
Is refurbished/tested DDR5 server memory reliable?
Yes — memory has no mechanical wear, and refurbished modules carry the same HPE PN as 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