Sourced for enterprise IT teams managing HP / HPE ProLiant DL360, DL380, ML350 and BL series platforms, the HP 81509-B21 (81509-B21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module) is a Memory component matched to OEM specifications. Each unit is verified against manufacturer datasheet revisions and is appropriate for new-build, expansion, or warranty-replacement procurement. Technical specifications include capacity of 8 GB, pc standard of PC4-21300, memory class of ECC, Unbuffered. Appropriate for virtualization hosts, application servers, in-memory analytics, render farms, CAD/EDA workstations, and any workload constrained by RAM rather than CPU. Our procurement team maintains active inventory of the 81509-B21 and verifies condition, firmware revision, and OEM part-number registry alignment for each unit prior to sale. Stocked units ship same-day on in-stock orders placed before 3pm ET. Pro Disk Network applies a 30-day functional warranty and accepts Net 30 / Net 60 terms for qualified business accounts. Free US ground shipping on orders over $150; same-day expedited (UPS Next Day Air, FedEx Priority) available at checkout.
The 81509-B21 is a HP memory component with capacity 8 GB, pc standard PC4-21300, memory class ECC, Unbuffered. Pro Disk Network sells the 81509-B21 for $188.74 with same-day US shipping and a 30-day free return guarantee.
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Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the 81509-B21 verified against the manufacturer datasheet and our internal lab benchmarks.
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Florida-Registered LLC — 7345 W Sand Lake Rd, Orlando FL 32819
Same-Day US Shipping — orders before 3pm ET ship today via FedEx/UPS
30-Day Free Returns — pre-paid label included on all US orders
Net 30 Available — for verified business buyers
2,000+ B2B Customers — MSPs, government, education, enterprise IT
Quick Answer: What servers is the 81509-B21 compatible with?
The 81509-B21 is a HP memory module. Confirm DIMM rank, voltage, and speed against the target server's supported memory list before deployment - mixed configurations may downclock to the slowest installed module. For server-specific population diagrams, email sales@prodisknetwork.com with your server serial number.
How fast does the 81509-B21 ship?
If in stock, the 81509-B21 ships same business day on US orders placed before 2 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
The 81509-B21 is deployed by US enterprises, MSPs, government, and education customers across multiple infrastructure scenarios. Below are the most common deployment patterns Pro Disk Network sees in real-world orders.
VMware Cluster Memory — Per-host memory expansion for vSphere ESXi hosts. Match DIMM rank and speed across all sockets to keep memory channels balanced.
In-Memory Database — SAP HANA, Redis Enterprise, Apache Ignite, Aerospike — workloads that scale linearly with DRAM capacity.
Hyper-V Cluster Node — Windows Server 2019/2022 Hyper-V hosts with Storage Spaces Direct. Dynamic memory allocation makes higher-density DIMMs cost-effective.
AI / ML Training — PyTorch and TensorFlow workloads benefit from large host memory pools for dataset preprocessing and CPU-side feature engineering.
New, Bulk, or Refurbished — Choosing Your Tier
Pro Disk Network offers the 81509-B21 across three procurement tiers. Each tier is fully functional and warranted; the choice comes down to budget, warranty length, and whether the deployment is production-critical or capacity-expansion.
Tier
Discount vs OEM List
Warranty
Best For
New (Sealed OEM)
25–40%
HP manufacturer warranty (1–5 yr)
Production-critical first-tier
New (Bulk OEM)
50–65%
3-year Pro Disk Network warranty
New cluster builds, secondary tier
Refurbished
75–85%
12-month advance replacement
Capacity expansion, lab, dev/test, EOL refresh
Bulk & Volume Pricing for 81509-B21
Ships from our Orlando, FL warehouse — same-day US dispatch on orders placed before 2pm ET. Net 30 terms available for verified businesses, government and education.
Volume discounts on the 81509-B21 are automatic at checkout. Net 30 terms available for verified businesses, government, and education. Email sales@prodisknetwork.com for orders above 100 units.
Quantity
Discount
Unit Price
1
0%
$188.74
5+
4%
$181.19
10+
8%
$173.64
25+
13%
$164.20
50+
18%
$154.77
100+
23%
$145.33
What is the 81509-B21?
The 81509-B21 is a HP server memory module with capacity 8 GB and pc standard PC4-21300, manufactured by HP. Pro Disk Network ships this part new and certified-refurbished from our US warehouse with same-day dispatch on orders placed before 3 PM ET, backed by a 30-day return guarantee.
Pros & Cons of 81509-B21
Pros
Lower cost than buying through the OEM channel
Same-day US shipping cuts deployment lead time
Bulk-of-eight pricing aligns with channel-balanced configurations
Cons
Memory must match existing DIMM rank/density for channel balance
Higher density modules can drop overall channel speed
BIOS update may be required on older revisions
Frequently Asked Questions about 81509-B21
Is the 81509-B21 a genuine HP part?
Yes. Pro Disk Network sources every 81509-B21 as factory-original HP inventory verified against the manufacturer parts registry before listing. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned HP servers, surface-tested, and re-warranted by Pro Disk Network for 12 months.
What servers is the 81509-B21 compatible with?
The 81509-B21 is a HP memory module. Confirm DIMM rank, voltage, and speed against the target server's supported memory list before deployment - mixed configurations may downclock to the slowest installed module. For server-specific population diagrams, email sales@prodisknetwork.com with your server serial number.
How fast does the 81509-B21 ship?
If in stock, the 81509-B21 ships same business day on US orders placed before 2 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
What is the warranty on the 81509-B21?
New 81509-B21 units carry the full HP manufacturer warranty (typically 1 to 5 years depending on product line). Refurbished and bulk-OEM units include a Pro Disk Network advance-replacement warranty (12 months refurbished, 36 months new bulk). DOA replacement is free within 30 days of receipt.
Do you offer bulk pricing for the 81509-B21?
Yes. Pro Disk Network offers automatic volume discounts at 10, 25, 50, and 100+ unit tiers. Net 30 terms are available for verified businesses, government, and education buyers. Email sales@prodisknetwork.com with the quantity and target ship date for a quote within one business day.
815097-S21 — 815097-S21 - HP 8GB DDR4-2666MHZ PC4-21300 ECC Registered CL19 288-Pin DIMM Single Rank 1.2V Memory Module for Gen10 Servers — $278.50
Pro Disk Network Buyer’s Guide: Memory
Compatibility: Rank, Density, and Channel Population Rules
For server memory, three numbers dominate compatibility: rank, density, and channel population. Mixing rank or density in the same channel forces the memory controller to fall back to the lowest-common-denominator speed and timings, sometimes by 200-400 MHz, which wastes the upgrade you just paid for. Before installing the 81509-B21, run the platform's memory configuration utility (Dell DSET, HPE iLO Memory tab, Lenovo XCC Memory page) to identify what's already populated.
Pricing Strategy: New, Bulk, or Refurbished
For production tier-1 databases (SAP HANA, Oracle Exadata-equivalent, SQL Server Always On), use new sealed OEM units only. For VDI hosts, hyperconverged clusters, and general-purpose virtualisation, bulk-OEM is the cost-optimal choice. For development environments, lab gear, and capacity expansion on aging hardware, refurbished is appropriate — the price savings are 60-75% versus new.