Home › Parts › HPE part numbers

P64705-B21: HPE 16GB (1x16GB) Single Rank x8 DDR5-5600 CAS-46-45-45 EC8 Registered Smart Memory Kit

HPEMemory

Also listed as: P65419-001, P64244-001, M321R2GA3PB0-CWM, HMCG78AGB842N, MTA9ASF2G72PZ-5G6 · made by Samsung

The HPE P64705-B21 is a 16GB single-rank x8 DDR5-5600 Registered ECC SmartMemory module engineered for 5th Generation Intel Xeon Scalable (Emerald Rapids) and AMD EPYC 9004/8004 processors on HPE ProLiant Gen11 servers. Operating at 1.1V with CAS latency 46, it incorporates on-die ECC plus sideband ECC (EC8) for mission-critical memory protection. When buying used or refurbished modules, buyers must check for undamaged gold contacts, verify heat spreader clip retention, and test rank compatibility against existing DIMMs.

Buy P64705-B21Sell yours

Specifications

Part numberP64705-B21
BrandHPE
Made bySamsung
TypeMemory
Other numbersP65419-001, P64244-001, M321R2GA3PB0-CWM, HMCG78AGB842N, MTA9ASF2G72PZ-5G6
Statuscurrent
Capacity (GB)16
Memory typeDDR5
SpeedDDR5-5600
Rank width1Rx8
Dimm typeRDIMM
Voltage1.1V
Cas latency46
Pin count288
Error correctionECC (EC8)
Generation fitGen11 / Gen12

About the P64705-B21

The HPE P64705-B21 represents the entry-density building block in HPE's DDR5-5600 SmartMemory portfolio, providing 16GB of registered memory organized in a single-rank 1Rx8 architecture. Tailored for HPE ProLiant Gen11 platforms utilizing 5th Gen Intel Xeon Scalable processors (Emerald Rapids) and 4th/5th Gen AMD EPYC server sockets, it runs at up to 5600 MT/s in 1 DIMM per channel (1DPC) deployments. It serves entry-level hypervisor hosts, edge appliances, and compute nodes requiring low latency without large memory footprint costs.

Compatibility

The module is physically and electrically restricted to DDR5 server sockets, preventing installation in DDR4-based Gen10 or Gen10 Plus systems. To achieve full 5600 MT/s throughput, the host server must feature supported 5th Gen Intel Xeon Scalable processors or AMD EPYC 9004 series CPUs; earlier 4th Gen Xeon (Sapphire Rapids) CPUs down-clock the bus to 4800 MT/s. Mixing x8 organized RDIMMs (1Rx8) with x4 organized RDIMMs (such as 1Rx4 or 2Rx4 kits) across the same memory channel is strictly disallowed by server memory population rules.

How to identify a genuine unit

Authentic HPE P64705-B21 modules display a dual-layered HPE SmartMemory label with Option Part Number P64705-B21, Spare Part Number P65419-001, and module build code 16GB 1Rx8 PC5-5600B-RC0-1010-XT. An onboard EEPROM SPD contains proprietary HPE cryptographically signed signature blocks that iLO 6 validates during POST. OEM markings from suppliers such as Samsung (M321R2GA3PB0-CWM), SK Hynix, or Micron are visible on the underlying PCB silkscreen.

Buying used

When purchasing surplus or pre-owned P64705-B21 DIMMs, inspect the 288-pin edge card contacts for physical scratching, solder peeling, or oxidation. Verify that the PMIC (Power Management IC) situated on the center of the module shows no overheating stress or cracked solder joints. Upon boot, ensure the system BIOS and iLO 6 register the modules as 'HPE SmartMemory Verified' rather than generic third-party memory, which would trigger disabled advanced memory fault alerts.

Reference prices (last 14 days, updated 2026-10-27)

New: USD 185 (1 sighting, Oct 2026)

Refurbished: USD 95 (1 sighting, Oct 2026)

All sightings
SellerConditionPriceNoteSeen
serversupply.comnewUSD 185New factory sealed retail kit2026-10-27
globalonetechnology.comrefurbishedUSD 95Refurbished memory module with 1-year warranty2026-10-27

Prices seen on public listings on the dates shown, before tax and shipping. Not an offer.

Fits these models

Equivalent part numbers

FAQ

Can P64705-B21 mix with 32GB 2Rx8 or 1Rx4 modules in a Gen11 server?

HPE ProLiant Gen11 rules prohibit mixing x8 organized DIMMs with x4 organized DIMMs in the same memory channel. Always populate identical rank and bit width across each memory channel.

Does P64705-B21 run at 5600 MT/s on 4th Gen Intel Xeon Scalable processors?

No, 4th Gen Intel Xeon Scalable (Sapphire Rapids) CPUs cap memory speed at 4800 MT/s. The module runs at 4800 MT/s on 4th Gen and reaches 5600 MT/s only on 5th Gen Xeon (Emerald Rapids) CPUs.

Buying or selling P64705-B21?

New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.

Buy P64705-B21Sell yours

Sources