P64336-B21 is the HPE option part number for 16GB (1x16GB) Single Rank x8 DDR5-4800 CAS-40-39-39 Unbuffered Standard Memory Kit. The kit contains one 16 GB unbuffered 288-pin DDR5 DIMM running at 4800 MHz (PC5-38400) with CAS latency timings of 40-39-39 at 1.2 V. It is a single rank module using x8 chip organization, and it is a system-specific upgrade rather than a generic module. HPE lists it as compatible with the ProLiant DL20 Gen11 and ML30 Gen11. If you are populating or expanding memory in either of those platforms, match this option number against the server's supported DIMM configuration and population rules before ordering.
HPE Option Part #: P64336-B21
HPE Spare Part #: P64633-001
HPE Assembly Part #: P64338-0A1
PRODUCT SPECIFICATIONS FOR P64336-B21:
- Capacity: 16 GB
- Upgrade Type: System specific
- Type: DRAM memory module
- Technology: DDR5 SDRAM
- Form Factor: DIMM 288-pin
- Speed: 4800 MHz (PC5-38400)
- Latency Timings: CL40 (40-39-39)
- Features: Single Rank, unbuffered
- Chips Organization: X8
- Voltage: 1.2 V
COMPATIBLE WITH:
PROLIANT DL SERIES
PROLIANT ML SERIES
** This list may not be complete. Contact us via Live Chat if you have any questions about compatibility.
FREQUENTLY ASKED QUESTIONS ABOUT P64336-B21
What is the difference between P64336-B21 and P64633-001?
They are the same physical DIMM under different HPE numbering schemes. This page, P64336-B21, is the option part number — the orderable number used when configuring or adding memory to a server. P64633-001 is the spare part number, used for service replacement of an installed module. This family also includes one assembly revision, and all numbers are listed in the cross-reference block on this page. An assembly part number identifies the manufactured build of the module as HPE assembled it.
Which servers does this memory support?
HPE lists this module as compatible with the ProLiant DL20 Gen11 and ML30 Gen11. It is a system-specific upgrade, so the module is qualified against those platforms rather than sold as a general-purpose DDR5 DIMM. Before ordering, confirm the server's maximum supported memory, the number of DIMM slots populated, and the DIMM population sequence documented for the platform, since those rules determine where the module must be installed.
What are the exact electrical and timing specifications?
This is a 16 GB DDR5 SDRAM DIMM in a 288-pin form factor. It runs at 4800 MHz, corresponding to PC5-38400, with CAS latency timings of CL40 (40-39-39). The module is single rank with x8 chip organization and operates at 1.2 V. It is unbuffered, meaning there is no register between the memory controller and the DRAM devices, which is typical for entry-level single-socket ProLiant platforms.
How many DIMMs are in this kit?
The kit is 1x16GB, so it contains a single 16 GB DIMM. To populate multiple slots you order multiple kits. Because the module is single rank with x8 organization, the rank count matters when mixing with other modules; consult the DL20 Gen11 or ML30 Gen11 memory population guidelines to confirm which combinations of rank and capacity are supported in your intended configuration.
Can this module be mixed with registered DDR5 DIMMs?
No. This is an unbuffered DDR5 DIMM, and unbuffered and registered modules are not interchangeable or mixable within a system. The DL20 Gen11 and ML30 Gen11 are the platforms HPE lists for this part, and any additional modules installed alongside it should be unbuffered DDR5 modules supported by those servers. Check the server memory documentation for the specific supported module types and mixing rules.
HPE PARTSURFER INFO FOR P64336-B21
| Spare PN | Description | |
|---|---|---|
| P64633-001 | SPS-DIMM,16GB PC5-4800B-E,2Gx8 |
Last Updated: 2026-06-26
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This product is warrantied against hardware failure for a period of 5 Years from the date of purchase. Before making a purchase, please take a moment to review our return policy below.
Returns
It is the customer's responsibility to verify compatibility with their machine(s) before placing an order. If an item is ordered by mistake, it can be returned for refund, minus a 25% restocking fee, within 5 business days of receipt. The cost of freight is not refundable.
Please be aware that factory-sealed equipment can only be returned if it remains unopened.
Defective Products
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Requesting an RMA
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