No products in the cart.
16GB DDR4 Server RAM – 2133MHz / 2400MHz / 2666MHz | 2Rx4 ECC Registered RDIMM
Upgrade your HPE ProLiant server with genuine 16GB DDR4 ECC Registered (RDIMM) SmartMemory — available in three speed grades: DDR4-2133, DDR4-2400, and DDR4-2666. All three variants feature Dual Rank × 4 (2Rx4) architecture, 288-pin form factor, 1.2V operation, and ECC data protection — making them the proven, enterprise-grade memory solution for HPE ProLiant Gen9 and Gen10 server platforms.
Whether you are expanding memory capacity on an existing Gen9 deployment or building out a new Gen10 server, these HPE SmartMemory modules deliver maximum compatibility, validated reliability, and the advanced RAS features that only HPE-qualified memory can unlock.
BUY THIS RAM HERE.
Quick Comparison — All Three Speed Variants
| Specification | DDR4-2133 | DDR4-2400 | DDR4-2666 |
|---|---|---|---|
| HPE Option Part Number | 726719-B21 | 836220-B21 | 835955-B21 |
| HPE Spare Part Number | 774172-001 | 846740-001 | 868846-001 |
| HPE Assembly Part Number | 752369-081 | 809081-081 | 840756-091 |
| Capacity | 16GB (1× 16GB) | 16GB (1× 16GB) | 16GB (1× 16GB) |
| Memory Standard | PC4-17000 | PC4-19200 | PC4-21300 |
| Speed | 2133 MT/s | 2400 MT/s | 2666 MT/s |
| CAS Latency | CL15 (15-15-15) | CL17 (17-17-17) | CL19 (19-19-19) |
| Rank / Width | Dual Rank × 4 (2Rx4) | Dual Rank × 4 (2Rx4) | Dual Rank × 8 (2Rx8) |
| DIMM Type | RDIMM — 288-pin | RDIMM — 288-pin | RDIMM — 288-pin |
| Operating Voltage | 1.2V | 1.2V | 1.2V |
| ECC | Yes | Yes | Yes |
| Peak Bandwidth | ~17,066 MB/s | ~19,200 MB/s | ~21,333 MB/s |
| Primary Generation | Gen9 (v3 CPU) | Gen9 (v4 CPU) | Gen10 (1st Gen CPU) |
💡 All three modules use the same 288-pin DDR4 RDIMM form factor and 1.2V operating voltage. However, they are each optimised for different server generations and CPU generations. Always match the DIMM speed to your server’s supported memory frequency. Running a faster DIMM in a slower-rated server will result in automatic downclocking to the server’s supported maximum speed.
Product 1 — HPE 16GB DDR4-2133 Dual Rank x4 ECC Registered Memory (726719-B21)
The HPE 726719-B21 is the first-generation DDR4 SmartMemory module for HPE ProLiant Gen9 servers equipped with Intel Xeon E5-2600 v3 (Haswell-EP) processors. Operating at 2133 MT/s with CL15 latency, it was the fastest DDR4 speed supported by the v3 processor generation. As a Dual Rank × 4 RDIMM it offers superior signal integrity and capacity for the 24-DIMM Gen9 platform.
| Specification | Details |
|---|---|
| Part Number (Option) | 726719-B21 |
| Part Number (Spare) | 774172-001 |
| Part Number (Assembly) | 752369-081 |
| Capacity | 16GB (1× 16GB) |
| Memory Technology | DDR4 SDRAM |
| Memory Standard | DDR4-2133 / PC4-17000 |
| Speed | 2133 MT/s |
| CAS Latency | CL15 (15-15-15) |
| Rank Configuration | Dual Rank × 4 (2Rx4) |
| DIMM Type | Registered DIMM (RDIMM) — 288-pin |
| Operating Voltage | 1.2V |
| Error Correction | ECC (Error Correcting Code) |
| Peak Bandwidth | ~17,066 MB/s (PC4-17000) |
| Dimensions (W × D × H) | 8.89 cm × 19.81 cm × 1.91 cm |
| Weight | 0.45 kg (1 lb) |
| Operating Temperature | 0°C to 85°C |
| Warranty | HPE Limited Warranty |
Compatible HPE Servers — DDR4-2133 (726719-B21)
| Server Family | Compatible Models (v3 CPU) |
|---|---|
| HPE ProLiant BL Gen9 | BL460c Gen9, BL660c Gen9 |
| HPE ProLiant DL Gen9 | DL60 Gen9, DL80 Gen9, DL120 Gen9, DL160 Gen9, DL180 Gen9, DL360 Gen9, DL380 Gen9, DL388 Gen9, DL560 Gen9, DL580 Gen9 |
| HPE ProLiant ML Gen9 | ML110 Gen9, ML150 Gen9, ML350 Gen9 |
| HPE ProLiant XL Gen9 | XL170r Gen9, XL190r Gen9, XL230a Gen9 |
| HPE Apollo | Apollo 4200 Gen9, Apollo 4500 Gen9 |
| HPE Synergy Gen9 | 480 Gen9, 620 Gen9, 660 Gen9, 680 Gen9 |
⚠️ This module is optimised for Intel Xeon E5-2600 v3 (Haswell-EP) processors. It will also function in v4 CPU systems but will operate at the server-rated DDR4-2133 speed. For v4 CPU-based Gen9 servers, the DDR4-2400 module (836220-B21) is recommended for maximum performance.
Product 2 — HPE 16GB DDR4-2400 Dual Rank x4 ECC Registered Memory (836220-B21)
The HPE 836220-B21 is the performance-tier DDR4 SmartMemory for HPE ProLiant Gen9 servers equipped with Intel Xeon E5-2600 v4 (Broadwell-EP) processors. Operating at 2400 MT/s, it delivers a bandwidth improvement over DDR4-2133 and is the correct module for any Gen9 server that has been upgraded from v3 to v4 CPUs. Also compatible across the full range of HPE Apollo and Synergy Gen9 platforms.
| Specification | Details |
|---|---|
| Part Number (Option) | 836220-B21 |
| Part Number (Spare) | 846740-001 |
| Part Number (Assembly) | 809081-081 |
| Capacity | 16GB (1× 16GB) |
| Memory Technology | DDR4 SDRAM |
| Memory Standard | DDR4-2400 / PC4-19200 |
| Speed | 2400 MT/s |
| CAS Latency | CL17 (17-17-17) |
| Rank Configuration | Dual Rank × 4 (2Rx4) |
| DIMM Type | Registered DIMM (RDIMM) — 288-pin |
| Operating Voltage | 1.2V |
| Error Correction | ECC (Error Correcting Code) |
| Peak Bandwidth | ~19,200 MB/s (PC4-19200) |
| Operating Temperature | 0°C to 85°C |
| Warranty | HPE Limited Warranty |
Compatible HPE Servers — DDR4-2400 (836220-B21)
| Server Family | Compatible Models (v4 CPU) |
|---|---|
| HPE ProLiant BL Gen9 | BL460c Gen9, BL660c Gen9 |
| HPE ProLiant DL Gen9 | DL60 Gen9, DL80 Gen9, DL120 Gen9, DL160 Gen9, DL180 Gen9, DL360 Gen9, DL380 Gen9, DL388 Gen9, DL560 Gen9, DL580 Gen9 |
| HPE ProLiant ML Gen9 | ML110 Gen9, ML150 Gen9, ML350 Gen9 |
| HPE ProLiant XL Gen9 | XL170r Gen9, XL190r Gen9, XL230a Gen9, XL250a Gen9, XL270d Gen9 |
| HPE Apollo Gen9 | Apollo 2000 Gen9, Apollo 4200 Gen9, Apollo 4500 Gen9, Apollo 4520 Gen9, Apollo 8000 Gen9 |
| HPE Synergy Gen9 | 480 Gen9, 620 Gen9, 660 Gen9, 680 Gen9 |
| HPE StoreEasy | StoreEasy 1850, 3850 Gateway |
⚠️ This module is optimised for Intel Xeon E5-2600 v4 (Broadwell-EP) processors. In Gen9 servers with v3 CPUs, this DIMM will operate at DDR4-2133. For Gen10 (Intel Xeon Scalable) servers, the DDR4-2666 module (835955-B21) is recommended for full performance.
Product 3 — HPE 16GB DDR4-2666 Dual Rank x8 ECC Registered Memory (835955-B21)
The HPE 835955-B21 is the HPE SmartMemory module designed for HPE ProLiant Gen10 servers running 1st Generation Intel Xeon Scalable processors (Skylake-SP). Operating at 2666 MT/s with CL19 latency, it is the standard speed for Gen10 Intel platforms and delivers the best balance of performance, capacity, and compatibility across the full DL, ML, BL, and Synergy Gen10 product range.
| Specification | Details |
|---|---|
| Part Number (Option) | 835955-B21 |
| Part Number (Spare) | 868846-001 |
| Part Number (Assembly) | 840756-091 |
| Capacity | 16GB (1× 16GB) |
| Memory Technology | DDR4 SDRAM |
| Memory Standard | DDR4-2666 / PC4-21300 |
| Speed | 2666 MT/s |
| CAS Latency | CL19 (19-19-19) |
| Rank Configuration | Dual Rank × 8 (2Rx8) |
| DIMM Type | Registered DIMM (RDIMM) — 288-pin |
| Operating Voltage | 1.2V |
| Error Correction | ECC (Error Correcting Code) |
| Peak Bandwidth | ~21,333 MB/s (PC4-21300) |
| Operating Temperature | 0°C to 85°C |
| Warranty | HPE Limited Warranty |
Compatible HPE Servers — DDR4-2666 (835955-B21)
| Server Family | Compatible Models (1st Gen Intel Xeon Scalable) |
|---|---|
| HPE ProLiant DL Gen10 | DL180 Gen10, DL325 Gen10, DL360 Gen10, DL380 Gen10, DL560 Gen10, DL580 Gen10 |
| HPE ProLiant ML Gen10 | ML110 Gen10, ML350 Gen10 |
| HPE ProLiant BL Gen10 | BL460c Gen10 |
| HPE ProLiant XL Gen10 | XL190r Gen10 |
| HPE Synergy Gen10 | 480 Gen10, 660 Gen10 |
| HPE Apollo Gen10 | Apollo DL385 Gen10 (AMD) |
⚠️ This module is designed for HPE Gen10 Intel Xeon Scalable servers. It is not recommended as a primary module for Gen9 servers. In Gen10 servers with 2nd Generation Intel Xeon Scalable CPUs (Cascade Lake), DDR4-2933 modules (P00920-B21) are available for even higher performance.
Speed Selection Guide — Which Module Do You Need?
| Your Server | Your CPU Generation | Recommended Module | Part Number |
|---|---|---|---|
| HPE ProLiant Gen9 | Intel Xeon E5-2600 v3 (Haswell) | DDR4-2133 | 726719-B21 |
| HPE ProLiant Gen9 | Intel Xeon E5-2600 v4 (Broadwell) | DDR4-2400 | 836220-B21 |
| HPE ProLiant Gen10 | 1st Gen Intel Xeon Scalable (Skylake) | DDR4-2666 | 835955-B21 |
| HPE ProLiant Gen10 | 2nd Gen Intel Xeon Scalable (Cascade Lake) | DDR4-2933 | P00920-B21 |
| HPE ProLiant Gen10 Plus / Gen11 | 3rd Gen Intel Xeon Scalable (Ice Lake) + | DDR4-3200 | P06033-B21 |
💡 Using a higher-speed module than your CPU supports will not cause damage — the DIMM will simply operate at the maximum speed supported by the processor. However, for optimal performance and HPE SmartMemory feature unlock, always use the module rated for your specific CPU generation.
DDR4 vs DDR3 — Why DDR4?
| Feature | DDR3-1600 (Previous Gen) | DDR4-2133 | DDR4-2400 | DDR4-2666 |
|---|---|---|---|---|
| Max Speed | 1600 MT/s | 2133 MT/s | 2400 MT/s | 2666 MT/s |
| Peak Bandwidth | ~12,800 MB/s | ~17,066 MB/s | ~19,200 MB/s | ~21,333 MB/s |
| Bandwidth vs DDR3-1600 | — | +33% | +50% | +67% |
| Operating Voltage | 1.5V / 1.35V (LV) | 1.2V | 1.2V | 1.2V |
| Prefetch Architecture | 8n | 8n | 8n | 8n |
| Bank Groups | No | Yes (4 groups) | Yes (4 groups) | Yes (4 groups) |
| On-Die ECC | No | No | No | No |
Key Features & Benefits
ECC — Enterprise Data Protection
- Error Correcting Code (ECC) automatically detects and corrects single-bit memory errors in real time
- Prevents silent data corruption — critical for databases, financial systems, and virtualisation hosts
- Reduces server downtime caused by memory-related crashes and blue screens
- Required for HPE SmartMemory Advanced ECC and Lockstep memory protection modes
Registered (RDIMM) — Signal Integrity at Scale
- Register buffers the address and command signals between the memory controller and DRAM chips
- Enables higher DIMM slot population than UDIMM — critical in 24-slot Gen9 and Gen10 servers
- Provides stable operation at high densities (e.g. 12–24 DIMMs per server) where unbuffered memory would fail
- Slight additional clock cycle latency vs UDIMM is offset by the stability and capacity advantages in server environments
Dual Rank (2R) — Performance & Capacity
- Dual rank organisation allows the memory controller to access two independent sets of DRAM chips per DIMM
- Enables rank interleaving — the memory controller can begin a new transaction on one rank while the other is refreshing, improving sustained throughput
- Higher capacity per DIMM slot compared to single rank — more memory in fewer slots
- Preferred configuration for memory-intensive workloads including virtualisation, databases, and analytics
HPE SmartMemory Exclusive Benefits
- Unlocks advanced HPE memory RAS features: Advanced ECC, Online Spare Memory, Mirrored Memory, Lockstep mode
- Integrated with HPE Active Health System (AHS) — continuous memory health monitoring and predictive failure alerting via iLO
- Enables HPE Workload Profiles for automatic memory sub-system tuning per workload type
- Manageable at scale via HPE iLO Amplifier Pack for fleet-wide memory health visibility
- Rigorously tested and qualified on HPE ProLiant platforms — exceeds JEDEC standard testing
- Fully supported under HPE warranty — generic third-party DIMMs may void server support in some configurations
Memory Population & Configuration Rules
- Always populate DIMMs in matched pairs per memory channel for dual-channel bandwidth and system stability
- Do NOT mix DDR3 and DDR4 modules in the same server — they are electrically and physically incompatible
- Do NOT mix RDIMM, UDIMM, and LRDIMM types within the same server
- If mixing DDR4-2133, DDR4-2400, and DDR4-2666 DIMMs in the same server, all DIMMs will run at the lowest installed speed
- Maximum memory speed is governed by the installed CPU — a faster DIMM cannot exceed the processor’s supported memory frequency
- For Advanced ECC, Mirroring, or Online Spare modes — consult the HPE server’s memory population guide for required DIMM slot configurations
- Always verify your specific configuration using the HPE Memory Configurator at hpe.com/info/HPESC
Sample Server Memory Configurations (16GB DIMMs)
| Server | DIMM Slots | Config | Total RAM | Recommended Module |
|---|---|---|---|---|
| HPE DL380 Gen9 (v3 CPU) | 24 | 4× 16GB | 64 GB | 726719-B21 |
| HPE DL380 Gen9 (v3 CPU) | 24 | 12× 16GB | 192 GB | 726719-B21 |
| HPE DL380 Gen9 (v4 CPU) | 24 | 4× 16GB | 64 GB | 836220-B21 |
| HPE DL360 Gen9 (v4 CPU) | 16 | 16× 16GB | 256 GB | 836220-B21 |
| HPE DL360 Gen10 | 24 | 8× 16GB | 128 GB | 835955-B21 |
| HPE DL380 Gen10 | 24 | 24× 16GB | 384 GB | 835955-B21 |
| HPE ML350 Gen10 | 12 | 12× 16GB | 192 GB | 835955-B21 |
Ideal Use Cases
- Server virtualisation — VMware vSphere, Microsoft Hyper-V, KVM
- Enterprise databases — Microsoft SQL Server, Oracle, MySQL, PostgreSQL
- ERP and business applications — SAP, Microsoft Dynamics
- File, print, and application server consolidation
- Security and surveillance recording servers
- VDI (Virtual Desktop Infrastructure) host platforms
- Backup and disaster recovery target servers
- Remote and branch office server deployments
- Memory capacity upgrades for existing Gen9 and Gen10 fleets
What’s in the Box
- 1× 16GB DDR4 ECC Registered HPE SmartMemory DIMM (as selected — 2133MHz, 2400MHz, or 2666MHz)
- HPE Limited Warranty
For full compatibility details, memory population rules, and server-specific guidance, use the HPE Memory Configurator and refer to your server’s QuickSpecs. All trademarks are the property of their respective owners.
