HPE P69728-B21 — 64GB 2Rx4 DDR5-6400 Server Memory
What it is
P69728-B21 is an HPE server memory module designed for HPE ProLiant and compatible HPE server platforms that support DDR5 DIMMs.
It’s a 64 GB DDR5-6400 memory module with a 2Rx4 (dual-rank ×4) organization — built to deliver high bandwidth, low latency, and strong performance for memory-intensive enterprise and virtualization workloads.
Why buyers pick P69728-B21 (plain English)
Big capacity with high speed
64 GB per module gives plenty of room for virtual machines, large databases, in-memory caches, and other demanding workloads, while the 6400 MT/s speed provides better throughput than earlier memory generations.
DDR5 performance & efficiency
DDR5 memory brings higher frequency, improved power management, and on-die ECC for greater reliability and efficiency compared with DDR4 — important for today’s data-centric applications.
Dual-rank organization
2Rx4 rank configuration can improve performance and memory access efficiency on platforms optimized for dual-rank DIMMs.
HPE-validated
Qualified and tested by HPE for compatibility and stability in supported ProLiant servers, so you get predictable behavior and vendor support.
60-second spec box (P69728-B21)
Capacity
64 GB
Memory type
DDR5 SDRAM
Speed
6400 MT/s
Rank / organization
2Rx4 (dual-rank ×4)
Form factor
Server DIMM (DDR5)
Error handling
On-die ECC (DDR5 native; system ECC support varies by platform)
Use case
Enterprise servers, virtualization hosts, high-performance databases, in-memory analytics.
Where it fits (and when to choose something else)
Perfect for:
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HPE ProLiant servers with DDR5 support
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Virtualized workloads and hyperconverged infrastructure
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Large in-memory databases and analytics
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Workloads that benefit from high memory bandwidth
Choose something else if:
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You need even higher capacity per DIMM → 128 GB or larger DDR5 modules
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Your platform only supports DDR4 → choose DDR4 memory instead
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You want registered or load-reduced DIMMs (on supported systems) → RDIMM/LRDIMM variants
TL;DR
P69728-B21 is HPE’s 64 GB 2Rx4 DDR5-6400 server memory module:
a high-speed, high-capacity DIMM designed for enterprise servers that need responsive memory performance for demanding workloads like virtualization and large-scale databases.

