P64707-B21: HPE 64GB 2Rx4 DDR5-5600 SmartMemory RDIMM
Also listed as: P64707-001, P65421-001, M321R8GA0PB0-CWM, HMCG94MEBRA · made by Samsung
An enterprise-grade 64GB dual-rank (2Rx4) DDR5-5600 registered ECC memory module certified as HPE SmartMemory for ProLiant Gen11 and Gen12 servers. Supporting maximum memory bus transfer rates of up to 5600 MT/s on 5th Generation Intel Xeon Scalable (Emerald Rapids) and AMD EPYC platforms, it unlocks advanced memory fault tolerance and predictive spare alerting in HPE Active Health System. When purchasing used, ensure the module contains official HPE SmartMemory SPD identification to enable supported clock speeds.
Specifications
| Part number | P64707-B21 |
|---|---|
| Brand | HPE |
| Made by | Samsung |
| Type | Memory |
| Other numbers | P64707-001, P65421-001, M321R8GA0PB0-CWM, HMCG94MEBRA |
| Status | current |
| Capacity (GB) | 64 |
| Interface | DDR5-5600 |
| Form factor | 288-pin RDIMM |
| Speed | DDR5-5600 MT/s |
| Rank width | 2Rx4 |
| Generation fit | Gen11 / Gen12 servers with 5th Gen Xeon or EPYC 9004/9005 |
About the P64707-B21
P64707-B21 is HPE's 64GB dual-rank (2Rx4) Registered DIMM (RDIMM) DDR5-5600 SmartMemory module, designed for high-density compute across ProLiant Gen11 and Gen12 servers. Built using Tier-1 DRAM dies from Samsung and SK hynix, it operates at 5600 MT/s at 1.1V with integrated On-Die ECC and an onboard Power Management IC (PMIC). The 64GB 2Rx4 configuration provides the ideal balance between memory capacity, high memory channel bandwidth, and cost-efficiency for virtualization platforms, high-performance computing, and enterprise database hosting.
Compatibility
This memory module is compatible with all HPE ProLiant Gen11 and Gen12 platforms supporting DDR5 memory, including the DL360 Gen11, DL380 Gen11, DL385 Gen11, DL325 Gen11, and DL560 Gen11. Operating speeds depend on the installed processor: it runs at the full 5600 MT/s when paired with 5th Gen Intel Xeon Scalable (Emerald Rapids) or AMD EPYC 9004/9005 processors, but automatically downclocks to 4800 MT/s when installed with 4th Gen Xeon (Sapphire Rapids) CPUs. It cannot be used in Gen10 or Gen10 Plus servers, which use DDR4 memory. The option part is P64707-B21, with spare numbers P64707-001 and P65421-001.
How to identify a genuine unit
A genuine P64707-B21 features an authentic HPE SmartMemory security label showing the option part number, spare part number, and assembly barcode alongside the OEM DRAM manufacturer label. In iLO 6 under Memory inventory, it is authenticated as HPE SmartMemory with authentic SPD programming, unlocking HPE Advanced Memory Error Detection and Fast Fault Tolerance. Generic retail DIMMs or relabelled modules lacking HPE EEPROM certification will be reported as third-party memory in iLO, potentially limiting operational clock frequencies.
Buying used
When sourcing pre-owned DDR5 server memory, inspect the gold edge contacts for deep scratches, cracks, or thermal oxidation, and inspect the onboard PMIC chip and surface-mount capacitors for physical damage. Request that the seller run MemTest86+ or verify the module through an HPE server POST diagnostic to ensure zero correctable or uncorrectable ECC error flags. Never mix DDR5 registered RDIMMs with non-ECC UDIMMs or unbuffered memory.
Reference prices (last 12 months, updated 2026-10-27)
New: USD 4,150 (1 sighting, Oct 2026)
All sightings
| Seller | Condition | Price | Note | Seen |
|---|---|---|---|---|
| serversupply.com | new | USD 4,150 | new factory sealed kit | 2026-10-27 |
Prices seen on public listings on the dates shown, before tax and shipping. Not an offer.
Fits these models
- HPE ProLiant DL380 Gen11
- HPE ProLiant DL360 Gen11
- HPE ProLiant DL385 Gen11
- HPE ProLiant DL325 Gen11
- HPE ProLiant DL560 Gen11
- HPE ProLiant ML350 Gen11
Equivalent part numbers
- Samsung M321R8GA0PB0-CWM Retail Samsung 64GB 2Rx4 DDR5-5600 RDIMM
- SK hynix HMCG94MEBRA OEM SK hynix 64GB DDR5-5600 RDIMM equivalent
FAQ
Can P64707-B21 run in a 4th Gen Xeon DL380 Gen11?
Yes, but it will automatically clock down to 4800 MT/s, the maximum memory speed supported by 4th Gen Intel Xeon Scalable processors.
Can I mix this DDR5 memory with DDR4 memory?
No. DDR5 and DDR4 memory modules are mechanically keyed differently and operate at different voltages.
Buying or selling P64707-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.
Sources
- HPE Server Memory QuickSpecs, checked 2026-10-27