Replacement for 81509-B21: Drop-In Alternatives We Stock
Looking for a replacement for the 81509-B21 (81509-B21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module)? Pro Disk Network ships HP drop-in replacements and equivalent modern parts from US inventory. Every alternate below is in-stock today with same-day shipping for orders placed before 2pm ET. If your unit is still under warranty, contact our engineering team — we offer cross-shipping for B2B customers on Net 30 terms.
About the 81509-B21
| SKU | 81509-B21 |
|---|---|
| Product | 81509-B21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module |
| Current price | $234.64 |
| Stock status | In Stock |
| Detail page | View 81509-B21 › |
Drop-in replacements for 81509-B21
Each part below is currently in our US warehouse, ships same-day for orders before 2pm ET, and includes our 90-day warranty. SKUs link to the full product page with photos, datasheets and B2B quote form.
HP26D4U9S8MD-8 - HPE 8GB DDR4-2666MHz PC4-21300 non-ECC Unbuffered CL19 288-Pin DIMM 1.2V Single Rank Memory Module
SKU: HP26D4U9S8MD-8
Price: $184.21
879505-S21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module
SKU: 879505-S21
Price: $234.64
879505R-B21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module
SKU: 879505R-B21
Price: $234.64
879505R-S21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module
SKU: 879505R-S21
Price: $234.64
879506-S21 - HPE 8GB PC4-21300 DDR4-2666MHz non-ECC Unbuffered CL19 UDIMM Memory Module
SKU: 879506-S21
Price: $234.64
P02888-B21 - HPE 8GB DDR4-2666MHz PC4-21300 ECC Registered CL19 288-Pin RDIMM 1.2V Single Rank Memory Module
SKU: P02888-B21
Price: $205.36
840756-K91 - HPE 16GB PC4-21300 DDR4-2666MHz ECC Registered CL19 RDIMM Memory Module
SKU: 840756-K91
Price: $186.59
840756-091U - HPE 16GB PC4-21300 DDR4-2666MHz ECC Registered CL19 RDIMM Memory Module
SKU: 840756-091U
Price: $186.59
P18958-B21 - HPE 32GB DDR4-2666MHz PC4-21300 ECC Registered CL19 288-Pin RDIMM 1.2V Dual Rank Memory Module
SKU: P18958-B21
Price: $289.47
HPE 815100-K21#0D1 32GB PC4-21300 DDR4-2666MHz ECC Registered CL19 RDIMM 1.2V Dual-Rank Memory Module
SKU: 815100-K21-0D1
Price: $299.33
P26034-001 - HPE 32GB DDR4-2666MHz PC4-21300 ECC Registered CL19 288-Pin RDIMM 1.2V Dual Rank Memory Module
SKU: P26034-001
Price: $299.33
How we pick replacements
Every recommendation above was selected using these criteria:
- Drop-in compatibility — same form factor (2.5"/3.5", PCIe slot, SFP port, etc.), so it fits the original chassis without modification
- Equivalent or better performance — matched on RPM/IOPS/speed/throughput, never downgraded
- Same-brand-preferred — we list the OEM-equivalent first when available, then trusted aftermarket
- Warranty coverage — 90-day Pro Disk warranty on every part, with 1-year option for B2B
- In stock today — never recommend a part that is on backorder
Need help confirming compatibility?
Our engineers validate every replacement against your specific server, switch, or chassis model before shipment. Email sales@prodisknetwork.com with your platform model (e.g., Dell PowerEdge R740, HP DL380 Gen10, Cisco Catalyst 9300) and we will confirm the exact part number that drops into your hardware.