Replacement for 20P3955: Drop-In Alternatives We Stock
Looking for a replacement for the 20P3955 (20P3955 - IBM 4840-561 System Board)? Pro Disk Network ships IBM 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 20P3955
| SKU | 20P3955 |
|---|---|
| Product | 20P3955 - IBM 4840-561 System Board |
| Current price | $765.66 |
| Stock status | In Stock |
| Detail page | View 20P3955 › |
Drop-in replacements for 20P3955
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.
36P3355 - IBM 1GB DDR-333MHz PC2700 non-ECC Unbuffered CL2.5 184-Pin DIMM Memory Module for SurePOS 4840
SKU: 36P3355
Price: $258.14
41D0535 - IBM 3.60GHz 800MHz FSB 1MB L2 Cache Socket LGA775 Intel Pentium 4 561 1-Core Processor
SKU: 41D0535
Price: $124.50
38L5750 - IBM 3.60GHz 800MHz FSB 1MB L2 Cache Socket LGA775 Intel Pentium 4 561 1-Core Processor
SKU: 38L5750
Price: $124.50
03N4801 - IBM Ultra-320 SCSI 6-Pack Disk Unit Backplane for 570 / 561 pSeries
SKU: 03N4801
Price: $157.07
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.