4X77A08633: Lenovo ThinkSystem 32GB TruDDR4 2933MHz (2Rx4 1.2V) RDIMM

Also listed as: 4X77A08633-01, 01KR355, M393A4K40CB2-CVF, B4AH, SP47A08633 · made by Samsung

The Lenovo 4X77A08633 is a 32GB dual-rank (2Rx4) registered DDR4 memory module running at 2933MHz with 1.2V operating voltage, engineered with Lenovo TruDDR4 signature memory technology for 2nd Generation Intel Xeon Scalable (Cascade Lake) ThinkSystem servers. Embedded signature microcode allows the server UEFI to authenticate the module, unlock certified memory timing tables, and output granular telemetry in XClarity Controller. It is one of the highest-volume memory modules traded on the second-hand enterprise market for Gen 1 ThinkSystem platforms. Buyers should check the heat spreader for genuine Lenovo security labels to avoid relabeled generic memory.

Specifications

About the 4X77A08633

4X77A08633 is Lenovo's mainstream 32GB dual-rank DDR4-3200 registered ECC memory module for ThinkSystem V2 rack, tower, and dense compute servers. In Lenovo's TruDDR4 lineup, it represents the primary workhorse module for dual-socket 3rd Gen Intel Xeon Scalable (Ice Lake) and AMD EPYC 7003 (Milan) systems. It replaced the older DDR4-2933 modules from the V1 server generation. This module is the baseline choice for general-purpose virtualization clusters, database backends, and container nodes where balancing memory bandwidth across 8 channels per socket is essential.

Compatibility

The module is engineered for ThinkSystem V2 platforms including the SR650 V2, SR630 V2, SR645, SR665, ST650 V2, and SD650 V2. It requires a compatible CPU memory controller supporting DDR4-3200 MT/s, such as Ice Lake Xeon or Milan EPYC. It does not fit ThinkSystem V3 servers, which use DDR5 exclusively with a physically incompatible 288-pin notch. A common mistake is attempting to mix this 2Rx4 dual-rank DIMM with single-rank (1Rx4) or quad-rank LRDIMMs within the same channel, which triggers memory initialization errors in XClarity.

How to identify a genuine unit

A genuine Lenovo module features a white barcode label displaying option part number 4X77A08633, spare FRU number 02JG673 or SP47A08633, and feature code B963. The underlying raw card is typically produced by Samsung (M393A4G43AB3-CWE) or Micron, but contains custom Lenovo SPD microcode. When installed, Lenovo XClarity Controller (XCC) identifies the DIMM with the TruDDR4 logo and confirms cryptographic authentication. Modules that display third-party memory warnings in UEFI or lack the Lenovo FRU label are likely standard whitebox RDIMMs without TruDDR4 tuning.

Buying used

When purchasing pulled or refurbished modules, ask the broker for MemTest86+ or Lenovo diagnostic verification logs showing zero correctable or uncorrectable ECC errors. Inspect the 288-pin gold contact edge for mechanical gouging, chipping, or missing surface-mount bypass capacitors near the module edge. Ensure the heat spreader is firmly bonded to the memory chips without bent clips. Surplus modules sold in sealed Lenovo packaging retain remainder factory warranty, while pulled units should come with a standard 30-day broker replacement guarantee.

Reference prices (last 14 days, updated 2026-10-27)

Prices seen on public listings on the dates shown, before tax and shipping. Not an offer.

Fits these models

• Lenovo ThinkSystem SR650
• Lenovo ThinkSystem SR630
• Lenovo ThinkSystem SR850
• Lenovo ThinkSystem SR950
• Lenovo ThinkSystem ST550
• Lenovo ThinkSystem SD530
• Lenovo ThinkAgile HX3320

Equivalent part numbers

• HPE P00924-B21 HPE 32GB (1x32GB) Dual Rank x4 DDR4-2933 CAS-21-21-21 Registered Smart Memory Kit HPE 32GB 2Rx4 DDR4-2933 SmartMemory RDIMM
• Dell AA579531 Dell 32GB 2Rx4 DDR4-2933 RDIMM

FAQ

Sources

• Lenovo ThinkSystem SR650 Server Product Guide - Memory Options, checked 2026-10-27