• Overview
  • Tech Specs
Mac Pro Tower, Windows PC, and Thunderbolt Expansion System
Install Four M.2 SSDs Into a PCIe Card Slot

x16 PCIe SlotHigh-speed Data Transfers

If you need to add internal storage to your computer setup and high-speed data transfers are critical to your work, don’t look to 2.5" SATA SSDs—you need an NVMe SSD-based upgrade. Today’s NVMe PCIe SSDs offer tremendous performance, easily outclassing 2.5" SATA SSDs. Sonnet’s M.2 4x4 PCIe card enables you to mount four M.2 NVMe PCIe SSDs(1) onto a single x16 card slot—it can transform the way you work.

With the Sonnet M.2 4x4 PCIe card installed in your Mac Pro® tower; Windows® PC desktop or server; or Thunderbolt™ to PCIe card expansion system with an available x16 PCIe slot, you can use it for instant-access media storage or as a high-performance scratch disk. Mac® users can even install macOS® on one SSD to create an incredibly fast boot drive.(2) However you use it, this card’s performance is impressive.

Sonnet M.2 4x4 PCIe Card

Performance Oriented

Sonnet’s M.2 4x4 PCIe card is a full-height, full-length PCIe 3.0 card with a 16-lane (x16) interface. Featuring a unique Sonnet-designed x16 PCIe bridge, the card devotes four lanes of PCIe 3.0 bandwidth to each SSD you install. When installed in a Windows PC’s PCIe 3.0 slot with four SSDs formatted in a RAID 0 configuration, the card is capable of 8,500 MB/s transfers. Aggregate transfer speeds from four non-RAIDed SSDs of up to 12,000 MB/s are possible! 

Four Lanes of PCIe 3.0 Bandwidth

Key Features

Adds Ultra-Fast SSDs to Your System—Mounts four M.2 SSDs (sold separately) in your Mac Pro's, desktop PC's, or Thunderbolt expansion chassis' x16 PCIe slot

High-Performance PCIe Interface—PCI Express 3.0 x16 host bus interface for high-performance applications

Superior Performance—Concurrent data transfers speeds up to 12,000 MB/sec(3)

Great Way to Add Up to 8TB of M.2 SSD Storage to Computers with Thunderbolt—Perfect for use in Sonnet's Echo™ Express III-D, Echo Express III-R, xMac™ mini Server, xMac Pro Server, and Thunderbolt expansion systems

RAID Support—Supports macOS and Windows RAID features

macOS Boot Support—Supports booting from JBOD (non-RAIDed) attached SSDs

NVMe Compliant SSDs—Typically no drivers required(4)

S.M.A.R.T. Support—Supports S.M.A.R.T. data reporting

Rugged Construction—Aluminum enclosure withstands heavy use

Thunderbolt Certified for Mac & Windows


iMac with Echo Express III-DThunderbolt Port? Connect Four SSDs Through One Cable

Got a Thunderbolt connection, but no PCIe card slot? Sonnet’s M.2 4x4 PCIe card is ideal for use in one of our Echo™ Express III-D, III-R, or xMac™ Thunderbolt to PCIe card expansion systems—the combo enables you to add up to four SSDs to any Mac with Thunderbolt 2 or Thunderbolt 3 ports, or Windows PC with Thunderbolt 3 ports.(5) 

Simple and S.M.A.R.T

Integrating a Sonnet M.2 4x4 PCIe card into your system is easy—just insert it into a x16 PCIe slot and then start your computer—NVMe compliance ensures the necessary drivers(4) are installed automatically. macOS 10.14.4+ and Windows 10 compatible; the Sonnet M.2 4x4 PCIe uses the operating system’s built-in drive formatting utilities to format the SSDs. Drive health monitoring is supported through S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) data reporting, too.


 Computer hardware shown in photos for illustration purposes; items sold separately.
See Tech Specs Tab for footnotes
Part No.  
FUS-SSD-4X4-E3 Sonnet M.2 4x4 PCIe Card
Warranty 2-year
Form Factor Computer Card
Internal Connectors Four M-keyed (NVMe) M.2 sockets

Mac Logo
SSDs Supported

Single-sided M.2 2280 NVMe PCIe SSDs(1)
PDF Download

macOS Boot Support Single SSD only:
  • Mac Pro 5,1 (Mid 2010 & Mid 2012)
  • Any Thunderbolt 3 Mac
Windows Boot Support No
NVMe Support Yes
S.M.A.R.T. Status Data Reporting Support Yes
RoHS Compliant Yes
Package Contents
  • Sonnet M.2 4x4 PCIe Card
  • Documentation


Specifications subject to change without notice.






Computer Compatibility

Mac Pro 5,1(6) (Mid 2010 & Mid 2012) with available full-length x16 PCIe slot

PC desktop or server with available full-length, full-height x16 PCIe slot (PCIe 3.0 slot is preferred)

OS Compatibility

macOS 10.14.4+ (macOS Mojave only)

Windows 10 (64-bit Edition Version 1809 or greater)

Thunderbolt Compatibility

Mac computer with Thunderbolt 3 or Thunderbolt 2 ports via a Thunderbolt 3 or 2 to PCIe card expansion system with available full-length x16 PCIe slot

Windows computer with Thunderbolt 3 ports via a Thunderbolt 3 to PCIe card expansion system with available full-length x16 PCIe slot

Technical Notes

  1. Only 2280 (80mm–the most common length) length M.2 SSDs and with memory components on only the top side are supported. M.2 SSD longer or shorter than 80mm don’t fit. M.2 SSDs with with components on both sides don’t fit.
  2. Booting from an external SSD in macOS 10.14.4+ requires enabling external booting in the security preferences that can be set in a command-R (recovery system) boot.
  3. This product’s performance will vary based on the type and number of SSDs used, the CPU speed (for RAID), and the PCIe architecture.
  4. Use of Samsung SSDs in computers running Windows requires the download and installation of NVMe drivers from Samsung; Microsoft Windows inbox NVMe drivers do not support Samsung SSDs.
  5. Performance in a Thunderbolt 3 PCIe expansion chassis limited by maximum Thunderbolt 3 PCIe bandwidth of 2800 MB/s. PCIe bandwidth of Thunderbolt 2 is about half of Thunderbolt 3.
  6. Mac Pro 5,1 requires a recommended Metal-compatible graphics card for macOS 10.4 (Mojave).


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