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4X77A08635: lenovo ThinkSystem 64GB TruDDR4 2933MHz (2Rx4 1.2V) RDIMM

lenovoMemory

Also listed as: 4X77A08635-01, 01KR357, SP47A08635, B4AG, M393A8G40MB2-CVF

64GB dual-rank DDR4-2933 registered ECC memory module engineered for high-density virtualization and database deployments in Lenovo ThinkSystem servers.

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Specifications

Part number4X77A08635
Brandlenovo
TypeMemory
Other numbers4X77A08635-01, 01KR357, SP47A08635, B4AG, M393A8G40MB2-CVF
TypeDDR4
Capacity (GB)64
Speed mhz2,933
Form factorRDIMM
Rank2Rx4
Voltage1.2
EccYes

About the 4X77A08635

The Lenovo 4X77A08635 is a high-density 64GB dual-rank registered ECC DDR4-2933 memory option designed for enterprise virtualization workloads. It sits at the top tier of dual-rank monolithic DDR4 configurations in Lenovo's Cascade Lake generation, providing maximum memory bandwidth without requiring higher-latency LRDIMMs. It was standard for memory-intensive enterprise server builds prior to the transition to DDR4-3200.

Compatibility

Engineered for Lenovo ThinkSystem SR650, SR630, SR850, and SR950 servers using 2nd Gen Intel Xeon Scalable processors. It operates at rated 2933 MT/s speed across standard 1 DPC and 2 DPC configurations depending on processor capabilities. It cannot be combined with load-reduced DIMMs, non-ECC memory, or newer DDR5 platforms such as ThinkSystem V3 servers.

How to identify a genuine unit

Recognizable by the Lenovo TruDDR4 label bearing option code 4X77A08635, FRU part number 01KR357, and feature code B4AG. The PCB carries 16Gb monolithic DRAM dies arranged in a 2Rx4 topology, commonly Samsung M393A8G40MB2-CVF. Lenovo XClarity Controller management consoles display genuine TruDDR4 authentication status in the hardware health tab.

Buying used

When buying pulled 64GB DDR4 RDIMMs, inspect the board surface for cracked decoupling capacitors or thermal pad degradation on the register clock driver. Verify that all modules in your order possess matching CAS latencies and rank structures to prevent memory bus downclocking. Request vendor memtest certificates verifying zero single-bit or multi-bit errors.

Reference prices (last 12 months, updated 2026-10-10)

Refurbished: USD 145 (1 sighting, Sep 2026)

Used: USD 125 (1 sighting, Oct 2026)

All sightings
SellerConditionPriceNoteSeen
eBayusedUSD 125eBay sold listing, bulk lot price2026-10-10
IT CreationsrefurbishedUSD 145Tested grade A working pull2026-09-15

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

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