IBM/Lenovo 16GB DDR4-2666 ECC Registered RDIMM for ThinkSystem Servers

The IBM 01DE973 is a 16GB DDR4-2666 (PC4-21300) ECC Registered DIMM with CL19 latency, 1.2V operation, and dual rank x8 organization — IBM/Lenovo-qualified server memory for Lenovo ThinkSystem and IBM System x platforms requiring DDR4-2666 ECC registered DRAM for enterprise workloads.

Key Features

• 16GB DDR4-2666 ECC Registered — higher frequency than DDR4-2400 for improved server memory bandwidth
• Dual Rank x8 (2Rx8) organization enabling broad DIMM slot compatibility
• Error Correcting Code (ECC) for hardware memory error detection and correction
• 1.2V low-voltage operation for energy-efficient 24/7 server operation
• IBM/Lenovo-qualified for ThinkSystem SR and IBM System x server platforms

Product Specifications

• Part Number: 01DE973
• Manufacturer: IBM / Lenovo
• Capacity: 16GB
• Type: DDR4 ECC RDIMM
• Speed: 2666MHz (PC4-21300)
• CAS Latency: CL19
• Voltage: 1.2V
• Pins: 288-pin

Memory Specifications

• Ranks x Width: 2Rx8 (Dual Rank x8)
• ECC: Yes (single-bit correction, multi-bit detection)
• Registered: Yes (RDIMM — buffered)
• JEDEC Compliant: DDR4-2666 JEDEC standard
• Operating Temperature: 0°C to 85°C

Performance Specifications

• Peak Bandwidth: ~42.6 GB/s (dual-channel at 2666MHz)
• Timing: 19-19-19
• Speed vs 46W0831: DDR4-2666 vs DDR4-2400 — ~11% higher memory bandwidth per channel
• Form Factor: Standard 1.2V server RDIMM height

Use Cases

• Memory expansion for Lenovo ThinkSystem SR530, SR630, SR650 DDR4-2666 platforms
• IBM System x server memory upgrades to DDR4-2666 for improved bandwidth
• Virtualization host RAM expansion requiring IBM/Lenovo-validated ECC RDIMMs
• Database server memory population requiring 2Rx8 16GB DDR4-2666 modules

Compatibility

• Compatible with Lenovo ThinkSystem SR series servers supporting DDR4-2666
• Compatible with IBM System x servers qualified for DDR4-2666 ECC RDIMMs
• 2Rx8 organization — verify server memory population rules before ordering
• Not compatible with consumer desktop or non-registered server DIMM slots

Frequently Asked Questions

What is the difference between 01DE973 (2Rx8) and 46W0831 (2Rx4) at 16GB?

Both are 16GB DDR4 ECC RDIMMs but differ in speed (2666MHz vs 2400MHz) and rank width (x8 vs x4). The 01DE973 offers higher bandwidth at DDR4-2666, while the x8 organization uses lower-density DRAM chips — verify which rank configuration your server's memory population guide requires.

Can I mix 01DE973 and 46W0831 in the same server?

IBM and Lenovo recommend populating all DIMM slots within a channel with identical modules. Mixing DDR4-2666 and DDR4-2400 DIMMs will cause the system to operate all channels at the lower 2400MHz speed. Consult your server's memory configuration guide.

Is the 01DE973 compatible with Intel Xeon Scalable (Skylake/Cascade Lake) processors?

Yes — Intel Xeon Scalable processors support DDR4-2666 on Lenovo ThinkSystem platforms. The memory controller will operate at DDR4-2666 speed when 01DE973 modules are installed in a supported configuration per Lenovo's memory population rules.

The IBM 01DE973 delivers DDR4-2666 ECC Registered performance in a 2Rx8 16GB module with IBM/Lenovo platform qualification — providing the higher memory bandwidth of DDR4-2666 over DDR4-2400 predecessors for server workloads where memory throughput directly impacts application performance in Lenovo ThinkSystem and IBM System x environments.