HP 408851-B21 2GB Kit (2x1GB) DDR2-667MHz RDIMM 1Rx4 CL5 Memory

Key specifications

The figures below come from this listing's own record. They are the ones that decide whether a part drops into an existing system.

• Memory Capacity: 2GB (2 x 1GB). Capacity of this module, not of the system.
• RAM Genre: RDIMM. The module type, such as registered, load reduced or unbuffered; types cannot be mixed in one system.
• Memory Technology: DDR2. The memory generation the module belongs to.
• RAM Speed: 667MHz. Rated speed; a bank runs at the speed of its slowest module.
• RAM Standard: DDR2-667/PC2-5300. The JEDEC speed grade printed on the module.
• Quantity of Pins: 240-pin. Pin count, which follows the generation and form factor.
• Rank: Single Rank x4. Rank count, which affects how heavily a memory channel can be populated.
• Column Access Strobe (CAS): CL5. CAS latency, in clock cycles.
• Product Voltage: 1.8V. The operating or input voltage recorded for this part.

Confirming fit

Memory Clearance does not publish a verified compatibility list for 408851-B21. Whether a part of this type is supported is defined by the system or switch vendor's own compatibility matrix, not by the part on its own.

The dependable check is the part number. Read the installed part number from the system's management interface and compare it with the number on this listing. If you send your server model with a quote request, it is checked against this part before you order.

Other HP Server Memory listings

Other parts in the same brand and category. These are not substitutes for this part number; check the specification before ordering.

• HP 483403-S21 8GB Kit (2x4GB) DDR2-667MHz RDIMM 2Rx4 CL5 Memory
• HP - D950463010I 64MB DDR-800MHz PC800 ECC Registered CL3 184-Pin DIMM Memory Module
• HP 593915-S21 16GB DDR3-1066MHz RDIMM 4Rx4 CL7 Memory
• HP 495605-S21 64GB Kit (8x8GB) DDR2-667MHz RDIMM 2Rx4 CL5 Memory
• HP 497767-S21 8GB Kit (2x4GB) DDR2-800MHz RDIMM 2Rx4 CL6 Memory
• HP 395409-48G 48GB Kit (12x4GB) DDR-333MHz RDIMM 2Rx4 CL2.5 Memory
• HP AH412A 128GB Kit (16x8GB) DDR2-533MHz RDIMM 4Rx4 CL4 Memory
• HP 405475-851 1GB DDR2-667MHz RDIMM 1Rx4 CL5 Memory
• HP 405475-951 1GB DDR2-667MHz RDIMM 1Rx4 CL5 Memory
• HP 500656-S21 2GB DDR3-1333MHz RDIMM 2Rx8 CL9 Memory

Common questions

Is 408851-B21 in stock?

Stock moves, so the quantity shown on this listing is the current figure. For a larger quantity, send the part number and how many you need and the answer comes back against that exact number. Quotes are answered weekdays 8:00 am to 5:00 pm PST.

Can I mix this module with the ones already installed?

Registered, load reduced and unbuffered modules cannot be mixed in one system, and a bank runs at the speed of its slowest module. Match the type and rank already installed, or replace the full bank.

How do I check what my server takes?

Read an installed part number from iDRAC or iLO and compare it with this listing, or check the platform's memory population table before ordering.

What do I send to get a price on 408851-B21?

The part number, the quantity, the condition you will accept and the server model it goes into. That is enough to answer in one pass.

Guides

• Memory population rules
• Reading memory and drive specs
• Finding the right OEM part number
• Buying in volume