Crucial

Crucial CT4G4SFS6266 4GB DDR4 2666MHz Laptop Memory

4.8 (58799 reviews)
4GB DDR4

A straightforward 4GB DDR4 laptop memory upgrade running at 2666 MHz for smoother everyday performance.

$29.95*
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*Price sourced from Amazon.com. Last updated:Jun 04, 2026.Price and availability are subject to change.

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Overview

The Crucial CT4G4SFS6266 is a 4GB DDR4 SODIMM running at 2666 MHz with CL19 latency, designed as a straightforward memory upgrade for laptops and compact systems. Manufactured by Micron — one of the world's largest memory producers — it benefits from the same silicon and quality testing found in OEM modules shipped with major laptop brands. The 260-pin SODIMM form factor and standard 1.2V operating voltage make it broadly compatible with laptops from the last several years that support DDR4 memory.

While 4GB on its own is modest by today's standards, this module serves well as an addition to an existing stick, bringing a system from 4GB to 8GB and potentially enabling dual-channel mode for improved bandwidth. Installation is typically tool-free, requiring only access to the laptop's memory compartment. For users looking to give an older or budget laptop a meaningful responsiveness boost without a large investment, this Crucial module is a reliable and affordable option.

Key Features

Optimized for next generation processors and platforms

Speeds up to 3200 MT/s and faster data rates are expected to be available as DDR4 technology matures

Increase bandwidth by up to 30%

Reduce power consumption by up to 40% and extend battery life

Faster burst access speeds for improved sequential data throughput

Specifications

Capacity
4GB
Memory Type
DDR4
Speed
2666 MHz
CAS Latency
CL19
Form Factor
SODIMM
Pin Count
260-pin
Voltage
1.2V
ECC
Non-ECC

Crucial CT2K16G4SFRA32A 32GB DDR4 3200MHz SODIMM Kit — Editorial Review & Compatibility Guide

The Crucial CT2K16G4SFRA32A is Crucial's 32GB (2×16GB) DDR4 3200MHz CL22 SODIMM laptop memory kit — designed for laptop / mini-PC / NUC / SFF systems with two SODIMM slots that need a maximum-capacity upgrade. Per Crucial's official CT2K16G4SFRA32A product page, the kit uses Micron-made memory dies with Crucial's QVL-tested compatibility across 90+ laptop / NUC models, ships at 3200MHz CL22-22-22-52, and includes a limited lifetime warranty. The CT2K nomenclature means "Crucial Twin-Kit" — matched pair purchase from a single manufacturing batch.

What the CT2K16G4SFRA32A Specifically Wins

  • Crucial-built (Micron parent company) — top-tier QVL compatibility — Crucial publishes a verified compatibility list of laptops + NUCs + SFF systems where this kit is tested-to-work. Reduces "will it work?" uncertainty
  • 3200MHz at CL22 is the laptop DDR4 sweet spot — most laptop motherboards lock at 3200MHz max regardless of installed module rate; CL22 (vs CL18-20 on some kits) is the latency tier most laptops accept stably
  • Matched 2-module kit from same manufacturing batch — eliminates timing mismatch issues that can occur when buying separate modules at different times
  • Lifetime limited warranty — Crucial / Micron RMA process for laptop SODIMM is reliable
  • Wide laptop compatibility — works in Dell Latitude / Inspiron / Vostro, HP EliteBook / ProBook / Pavilion, Lenovo ThinkPad / IdeaPad / Legion, ASUS ROG / VivoBook / Zenbook, MSI Modern / Stealth / Gaming, Acer Aspire / Predator, and many more
  • Compatible with Intel NUC, Mini PC, SFF builds — Intel NUC 10/11/12 series, ASUS PN50/PN51, GMK NucBox, Beelink mini PCs
  • Backward compatible with 2400/2666MHz laptops — falls back to lower JEDEC speed automatically on older platforms
  • Single-rank or dual-rank automatic — works in either single-rank or dual-rank laptop slots

Where the CT2K16G4SFRA32A Specifically Fits

  • Laptop RAM upgrade from 8GB / 16GB to 32GB — common upgrade path for productivity / creative workflows
  • Intel NUC 10 / 11 / 12 mini PC build needing maximum 32GB
  • Mini PC home server / NAS build (ASUS PN50, Beelink, GMK NucBox)
  • Mobile workstation laptops (Dell Precision, HP ZBook, Lenovo ThinkPad P-series) needing 32GB for CAD / 3D / video work
  • Gaming laptops (ASUS ROG, Razer Blade, MSI Stealth) at 16GB needing upgrade for higher RAM-demand games
  • Mac mini / Mac (Intel-based) upgrade — Intel Mac mini 2018+ supports SODIMM DDR4. Apple Silicon Macs are NOT user-upgradeable
  • Older laptop revival — Lenovo ThinkPad T480/T490 + similar that ship at 8GB benefit substantially from 32GB upgrade
  • Virtualization on laptop — running multiple VMs / development environments needs 32GB minimum
  • Photo editing on laptop — Lightroom + Photoshop benefit from 32GB
  • Video editing on laptop — 4K editing in Premiere Pro / Final Cut Pro / DaVinci Resolve needs 32GB minimum

Honest Limits Buyers Should Know

  • Verify the laptop's MAX RAM specification first. Many laptops cap at 32GB total; some at 64GB; very few support more. Check the manufacturer's spec sheet OR Crucial's compatibility tool BEFORE purchase
  • Verify laptop has TWO SODIMM slots. Many ultrabooks (MacBook Air, XPS 13, Surface Laptop) have soldered RAM — non-upgradeable. Some laptops have one SODIMM + soldered. The CT2K is a 2-stick kit; single-slot laptops cannot use the full kit
  • Performance gain from upgrading 16GB → 32GB depends on workload. Light browsing / email users see no improvement. Heavy multi-app users (developers, content creators, virtualization) see substantial improvement. Verify the bottleneck is RAM (Activity Monitor / Task Manager memory pressure) before upgrading
  • CL22 latency is mainstream — not enthusiast. Some gaming SODIMM kits at CL20 / CL18 exist for slight performance edge. Laptop platforms rarely benefit meaningfully; the CL22 is the safe-and-stable option
  • Soldered-RAM laptops cannot use this kit AT ALL. MacBook Air / MacBook Pro M1/M2/M3/M4, Surface Laptop Studio, XPS 13/15/17 (most generations), Dell Latitude 7000 series — soldered RAM is fixed at factory. Verify socket type before buying
  • Older laptops with 1.2V DDR4 requirement. The CT2K kit operates at 1.2V (standard DDR4). Older DDR3L laptops require DDR3L SODIMM, not DDR4 — these are NOT cross-compatible
  • NOT compatible with DDR5 laptops. Current Intel 12th-gen+ laptops use DDR5 SODIMM. The CT2K is DDR4 only. For DDR5 laptops, look at CT2K8G4SFRA32A's DDR5 successor (CT2K8G5S6800SA or similar)
  • BIOS update sometimes needed. Some older laptops require BIOS update to recognize 32GB modules. Verify BIOS is current before upgrade
  • Installation requires laptop disassembly. Most laptops require removing bottom panel, locating SODIMM slots, snapping out old modules + inserting new. Manufacturers' instructions vary; consult laptop's service manual or iFixit guide

Where Buyers Should Look Elsewhere

  • DDR5 laptops → Crucial DDR5 SODIMM family (different SKU prefix)
  • Higher capacity (64GB) in supported laptops → 2× 32GB SODIMM kits (CT2K32G4SFRA32A) — verify laptop supports 64GB max
  • Single 16GB module (8GB → 24GB upgrade) → CT16G4SFRA32A single module — replaces one of two pre-installed modules
  • Single 32GB module (laptop with 1 SODIMM slot) → CT32G4SFRA32A — single high-capacity module
  • Older DDR3 / DDR3L laptops → Crucial DDR3L SODIMM family (CT * SODIMM DDR3 SKUs)
  • Premium / enthusiast laptop SODIMM → Kingston Fury Impact, G.SKILL Ripjaws DDR4 SODIMM at lower CL latency
  • Apple Silicon Mac users → cannot upgrade RAM; need to buy higher-RAM model from Apple direct

Sources & Citations

  1. Crucial, "CT2K16G4SFRA32A product page," crucial.com (accessed 2026-05-18)
  2. Crucial Compatibility Tool, "Laptop / NUC / SFF SODIMM compatibility lookup," crucial.com (accessed 2026-05-18)
  3. Tom's Hardware, "Laptop RAM upgrade guide and SODIMM compatibility," tomshardware.com (accessed 2026-05-18)
  4. iFixit, "Laptop SODIMM installation guides," ifixit.com (accessed 2026-05-18)

Last verified: 2026-05-18

Now that you've seen the details — ready to take a closer look?

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Pros & Cons

👍 Pros

  • Backed by Micron, one of the largest memory manufacturers, ensuring component-level quality control
  • Standard 1.2V DDR4 operation keeps power consumption low in battery-powered devices
  • 260-pin SODIMM form factor is compatible with a wide range of laptops
  • Simple tool-free installation in most laptops with accessible memory slots

👎 Cons

  • 4GB capacity is minimal for modern multitasking and may only serve as a supplemental module
  • 2666 MHz speed may be downclocked in systems with a lower maximum supported memory speed
  • Single-module configuration does not enable dual-channel memory performance on its own
  • CL19 latency is on the higher side compared to lower-latency DDR4 options

Frequently Asked Questions

It is a 260-pin SODIMM designed for laptops and small form factor systems that support DDR4 2666 MHz memory.
No, this is a non-ECC memory module intended for standard consumer and business laptops.
It runs at 1.2V, which is the standard voltage for DDR4 memory.
This is a single 4GB module. If your laptop has an available memory slot, you can add it alongside existing RAM.
The CAS latency is CL19.