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Samsung

Samsung 64GB DDR4-2666 ECC RDIMM

M393A8K40B22-CWD
Samsung DDR4 RDIMMmemory64GBDDR4-2666RDIMM
$6.23/GB
$399.00
newIn Stock
This offer: sold by Aventis Systems · Amazon says New / Unknown
Prices refresh about once a day
Price updated
Price accurate as of Oct 22, 2026, 10:19 AM
Buy on Amazon

The Samsung 64GB DDR4-2666 ECC RDIMM is a 64GB DDR4 ECC server memory module in new condition. It is in stock at $399.00 - $6.23/GB.

Part number: M393A8K40B22-CWD — decoded, with sibling variants and the warranty check.

Same capacity, other options
DriveInterfaceCond$/TBPrice
Supermicro 64GB DDR4-2666 ECC LRDIMMDDR4-2666New$6384.00$399.00Buy on Amazon
A-Tech 64GB DDR4-2666 ECC LRDIMMDDR4-2666New$6560.48$410.03Buy on Amazon
A-Tech 64GB DDR4-2933 ECC RDIMMDDR4-2933New$10297.76$643.61Buy on Amazon
A-Tech 64GB DDR4-2933 ECC RDIMMDDR4-2933New$10580.16$661.26Buy on Amazon
Model context

Part of the Samsung line we track.

Quick Verdict

Samsung 64GB DDR4-2666 ECC RDIMM at $6.23/GB. Warranty varies by seller. Verify your server's QVL before purchase.

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Specifications

Capacity64GB
Module TypeRDIMM
GenerationDDR4
Speed2666 MT/s
ECCYes
Rank / Org—
Warranty—
ASINB0B86G8LQ6
Market context

Against every other module we have an in-stock price for today, this one is cheaper per gb than 93% of them (37 of 40). The cheapest we can currently buy is $4.92/GB; the middle of the market is $12.25/GB.

Compare against every 0.0625TB drive we track →Cheapest per terabyte, all categories →Category price trends →
How it compares - 64GBDDR4-2666
#1Supermicro 64GB DDR4-2666 ECC LRDIMM
$6.23/GB
#2Samsung 64GB DDR4-2666 ECC RDIMMTHIS DRIVE
$6.23/GB
#3A-Tech 64GB DDR4-2666 ECC LRDIMM
$6.41/GB

Compare to similar 64GB DDR4-2666 modules

Supermicro
64GB DDR4-2666 ECC LRDIMM
$6.23/GB
$399.00
new
A-Tech
64GB DDR4-2666 ECC LRDIMM
$6.41/GB
$410.03
new

Works in these servers

Dell R650
DDR4 · 32 slots · memory rules + live prices →
Dell R730
DDR4 · 24 slots · memory rules + live prices →
Dell T440
DDR4 · 16 slots · memory rules + live prices →
HPE DL360 Gen10
DDR4 · 24 slots · memory rules + live prices →
HPE DL380 Gen10
DDR4 · 24 slots · memory rules + live prices →
HPE ML350 Gen10
DDR4 · 24 slots · memory rules + live prices →
Lenovo SR630
DDR4 · 24 slots · memory rules + live prices →
Lenovo SR650
DDR4 · 24 slots · memory rules + live prices →

Compatibility per each platform's verified OEM rules (generation, module type, speed floor, per-DIMM max). Always confirm against the vendor QVL for your exact configuration.

Find the right config for your server - the Memory Finder turns those rules into priced DIMM configurations.

Also appears in

Server memory
Other pages
Best-of verdicts
AI storage

Frequently Asked Questions

Yes. At our last check it was $399.00 ($6,384.00 per terabyte at its 0.0625TB capacity), sold new under ASIN B0B86G8LQ6. Amazon sets the final price at checkout.

This listing (M393A8K40B22-CWD, ASIN B0B86G8LQ6) carries no renewed, recertified, refurbished or pulled claim in its title, and Amazon reports it as new. On this site that is what "new" means: sold as factory-new.

This row (ASIN B0B86G8LQ6) is stored as a DDR4 RDIMM at DDR4-2666. A DDR4 module fits only a DDR4 platform (the keying and voltage differ by generation), and registered and unbuffered modules are not interchangeable - check your board's memory specification for DDR4 RDIMM support.

Use Case Scenarios

🖥️
Virtualization Host Density
Proxmox, ESXi or Hyper-V host packing more VMs per socket.
✓ Excellent fit
RAM is the binding constraint on VM density long before CPU. Adding 64GB ECC modules lets a host carry more guests per socket, and ECC prevents a single bit-flip from corrupting a guest's memory.
💾
ZFS ARC Cache
TrueNAS or ZFS server where read performance depends on cache hit rate.
✓ Excellent fit
ZFS turns every spare gigabyte into ARC read cache — more RAM directly raises cache hit rates on active datasets. ECC is strongly recommended for ZFS, whose integrity guarantees assume trustworthy memory.
🗄️
Database Working Set
PostgreSQL, MySQL or in-memory analytics needing the working set resident.
✓ Excellent fit
Databases live or die on buffer pool size. Fitting the working set in memory converts disk reads into RAM reads — a latency improvement no storage upgrade matches. ECC protects against silent corruption in long-running instances.
🏠
Homelab ECC Upgrade
Home server or NAS build stepping up from consumer memory.
~ Good fit
For 24/7 homelab duty, ECC server memory at today's used/refurb prices is often cheaper per GB than new consumer RAM — with error correction included. Verify your board and CPU actually support ECC before buying.

Maintenance & Troubleshooting

Maintenance Checklist

On installRun a full memtest86+ pass
Boot memtest86+ and let it complete at least one full pass before trusting the module with production data. Catches infant-mortality defects and seating problems immediately.
On installVerify detected speed and channel population
Check BIOS/IPMI that the module runs at the expected MT/s and that channels are populated per the motherboard manual's DIMM order. Uneven population silently costs bandwidth.
MonthlyReview ECC error counters
Check IPMI/iDRAC/iLO event logs, or edac-util on Linux, for corrected ECC errors. Occasional corrected errors are normal; a climbing count on one DIMM predicts failure — replace it.
AnnuallyReseat and dust during maintenance windows
Airflow debris and socket oxidation cause intermittent errors. During planned downtime, blow out slots and reseat modules showing any corrected-error history.

Troubleshooting Guide

Cause: Unsupported module type (UDIMM vs RDIMM), wrong DDR generation, or incorrect slot population order.
Fix: Confirm the platform supports this exact type and generation (check the QVL), install in the manual's specified slot order, and reseat firmly until both latches click.