Replacement for 251998-B21: Drop-In Alternatives We Stock
Looking for a replacement for the 251998-B21 (251998-B21 - Compaq 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module)? Pro Disk Network ships 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 251998-B21
| SKU | 251998-B21 |
|---|---|
| Product | 251998-B21 - Compaq 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module |
| Current price | $173.28 |
| Stock status | In Stock |
| Detail page | View 251998-B21 › |
Drop-in replacements for 251998-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.
267907-B22 - Compaq 512MB DDR-266MHz PC2100 ECC Unbuffered CL2.5 184-Pin DIMM Memory Module
SKU: 267907-B22
Price: $109.28
175925-882 - Compaq 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Dual Rank Memory Module
SKU: 175925-882
Price: $173.28
306984-001 - Compaq 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module for Desktop PCs
SKU: 306984-001
Price: $173.28
285650-001 - Compaq 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module for EVO D500 / D510c / D310 / D315 / Evo W4000
SKU: 285650-001
Price: $173.28
251584-041 - Compaq 512MB DDR-266MHz PC2100 ECC Registered CL2.5 184-Pin DIMM Memory Module
SKU: 251584-041
Price: $103.26
260655-002 - Compaq 512MB DDR-266MHz PC2100 ECC Registered CL2.5 184-Pin DIMM Memory Module
SKU: 260655-002
Price: $103.26
257973-B21 - Compaq 512MB Kit (2 X 256MB) DDR-266MHz PC2100 ECC Registered CL2.5 184-Pin DIMM Memory
SKU: 257973-B21
Price: $173.68
257974-B21 - Compaq 1GB Kit (2 X 512MB) DDR-266MHz PC2100 ECC Registered CL2.5 184-Pin DIMM Memory for ProLiant Servers
SKU: 257974-B21
Price: $236.21
282436-B22 - Compaq 1GB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module
SKU: 282436-B22
Price: $94.88
267905-B21 - Compaq 128MB DDR-266MHz PC2100 ECC Unbuffered CL2.5 184-Pin DIMM Memory Module for W4000 Workstation
SKU: 267905-B21
Price: $98.05
175923-001 - Compaq 128MB DDR-266MHz PC2100 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory
SKU: 175923-001
Price: $98.05
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.