• Overview
  • Tech Specs

SuperSpeed USB-C 10Gbps • USB-C Charge & Sync • Two Ports with up to 15W Power per Port

Amazing USB 3.2 Gen 2 Performance
Add Two USB-C 10Gbps Ports to Mac Pro, Windows, and Linux Computers with PCIe Slots; and Thunderbolt to PCIe Card Expansion Systems

Up to 2 Times the performance USB 3.0 and USB 3.1 Gen 1 Connections

When it comes to supporting the fastest USB drives available, your computer’s USB 3.0 ports are perfectly adequate…for connecting peripherals that don’t depend on the ultimate USB 3.2 speeds. However, common USB 3.0 ports can be underachievers—at 5Gbps, they can’t support the maximum performance from many storage devices, and may not provide enough power to enable them to operate. You need SuperSpeed USB-C®!

The Allegro™ USB-C PCIe(1) card supports data transfers at up to twice as fast as USB 3.0, and can also deliver 15W of power per port to USB-C bus-powered devices (three times the 4.5W specified in the USB 3.0 spec). Don’t settle for mediocre performance or insufficient power for the fastest SSDs—install an Allegro USB-C card to instantly add two Gen 2 USB 3.2 ports to your system and take full advantage of today’s SSD performance.

Full Power

Sonnet specially engineered the Allegro USB-C card to provide 15W of power through each of its ports. The ports communicate with the host that 3A of VBUS current is available, enabling this Sonnet solution to support USB-C bus-powered SSDs and SSD RAID devices that need 15W during demanding write operations.

The Sonnet Speed Advantage

Featuring the latest high-performance USB 3.2 Gen 2 controller from ASMedia—the ASM 3142—the Allegro USB-C PCIe card supports concurrent data transfers up to 925 MB/s when connected to a two USB-C Gen 2 NVMe SSD devices! Most other cards limit concurrent transfers to half that, a significant disadvantage when time is of the essence.


Compatible with 2023 Mac Pro

Key Features

Two SuperSpeed USB-C 10Gbps Ports—Adds two USB-C 10Gbps ports to your Mac Pro®, Windows® PC, or Linux® computer with PCIe slots; or Thunderbolt™ to PCIe card expansion system

Amazing Performance—Transfers data up to 960 MB/s from a single drive, and up to 925 MB/s from each of two drives simultaneously

Super-Powered Ports—Supports USB-C bus-powered SSD, SSD RAID, and hard drive devices with up to 15W (3.0A) power per port

Protected Ports—Independent power regulation isolates each port to prevent cross-coupled power glitches that may cause accidental disconnects

Resettable Fuses—Device overcurrent fuses are resettable—just shut down your machine to reset a fuse without permanent damage to card or computer

PCIe Data Link Auto-Negotiation—Card auto-negotiates one lane data link in a PCIe 3.0 slot and two lanes in a PCIe 2.0 slot, ensuring full 10Gbps performance in either generation PCIe slot

Broad USB Device Support & Compatibility—Supports storage, hubs, and other USB-IF compliant USB devices

Supports Hot-Swappable Device Connection—Plug in and disconnect peripherals without shutting off your computer

Add USB 3.2 Gen 2 to Thunderbolt Expansion Systems—Add two SuperSpeed USB-C 10Gbps ports to Thunderbolt to PCIe card expansion systems

Easy Installation—Quick and easy user installation into any available PCIe slot

Sonnet PCIe 3.0 x2 (16 Gb/s) Chart

Others PCIe 3.0 x2 (8 Gb/s) Chart

Sonnet Power Circuit Advantages:

USB-C Ports Power Icon

Regulates Power to Each Port

Ordinary USB-C adapter cards deal with power delivered through the ports as an afterthought, requiring an additional power source for the card and providing little regulation. The Allegro is no ordinary adapter card. The card regulates its own power without requiring a back-of-the card power cable connection, thus enabling full compatibility in any computer or Thunderbolt expansion system that doesn’t have these power connectors available.

Sonnet’s Allegro PCIe card is unique in regulating power to each port independently, giving each one protection from power glitches on the adjacent port. Without this protection (such as found on an ordinary card), connects and disconnects of one device may cause auto-disconnects of the other.

Resettable Fuses Icon


Resettable Fuses

The Allegro features a resettable fuse on each port to protect the card and computer should there be a cable or peripheral failure. Should a fuse trip on the Sonnet card, you can reset it simply by shutting down the computer.

Allegro USB-C 15W Power Per Port Illustration

Specially engineered to provide 15W of power through each port to support USB-C
bus-powered SSDs and SSD RAID devices that need 15W during demanding write operations

Mac Computers with Echo Express III-D

Add USB 3.2 to Your Thunderbolt Mac

Got a Mac with a Thunderbolt connection, but no PCIe slot? The Allegro is ideal for use in Sonnet’s Thunderbolt 2 and Thunderbolt 3 to PCIe card expansion systems, including Echo Express™ and xMac™ desktop and rackmount systems.

Easy Installation

This Allegro USBC-C PCIe installs easily into any PCIe x4 (mechanical) slot; both low-profile and full-height mounting brackets are included. The Sonnet card features hot-pluggable and hot-swappable device connection support with automatic device configuration, and works with all USB-IF compliant USB peripherals.

 Computer hardware shown in photos for illustration purposes; items sold separately.
See Tech Specs Tab for footnotes
Part No.  
USB3C-2PM-E Allegro USB-C PCIe Card(1)
Warranty 2-year
Form Factor PCIe x4 low-profile computer card; full-height mounting bracket attached, low-profile bracket included
Bus Interface PCI Express 3.0 x2
Peripherals Supported
  • Industry standard USB 3.2 Gen 1, Gen 2 & 2x2; USB 3.1 Gen 1 & 2; USB 3.0, 2.0 and 1.1
  • Thunderbolt 3-only peripherals are NOT supported
Bus Powered Peripherals Supported
  • HD, SSD, SSD RAID, DVD & Blu-ray devices
  • 3A per port advertised using USB Type-C Charging
  • 15W per port for operation or charging
Cables Supported
  • USB-C 10Gbps
  • USB-C 5Gbps (not recommended)
  • Thunderbolt 3 40Gbps
    • These TB3 cables support Sonnet ThunderLok 3
  • Thunderbolt 3 20Gbps (0.5-, 0.7-, 0.8-meter cables only)
Chipset ASMedia 3142(2)
RoHS Compliant Yes
Package Contents
  • Allegro USB-C PCIe Adapter Card with attached full-height mounting bracket
  • Low-profile mounting bracket
USB Support  
Number of Ports 2 external
Standard Complies with OHCI (Open Host Controller Interface), EHCI (Enhanced Host Controller Interface), and xHCI (eXtensible Host Controller Interface) standards
UASP USB attached SCSI protocol supported under
macOS 10.12+, Windows 10
Chipset Throughput 16 Gbps combined port throughput
Number of Devices Supported Up to 31
Hot Plug Supports hot-pluggable and hot swappable device connection
Boot Support No computers support booting at this time.


Specifications subject to change without notice.

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Mac Compatibility

Mac Pro® 3,1(3),  4,1,  5,1, 7,1 (2019), or 14,8 (2023)(4)

macOS 10.12.6+

macOS Sonoma compatible

Windows Compatibility

Computer with PCIe 1.1, 2.0, or 3.0 slots (3.0 slot preferred)
(Not compatible with most PCIe 4.0 slots)

Windows 11, 10, 8.1, 7

Windows Server 2022, 2019, 2016, 2012, 2008 (64-bit editions)

Linux Compatibility

Computer with PCIe 1.1, 2.0, or 3.0 slots (3.0 slot preferred)
(Not compatible with most PCIe 4.0 slots)

Linux Kernel 5.4.0+

Ubuntu 20.04.1+

Thunderbolt PCIe Expansion System Compatibility

Supports USB 3 devices when card is installed in a Thunderbolt to PCIe Card Expansion System

Technical Notes

  1. Product complies with USB 3.2 Gen 2 specification, which supersedes USB 3.1 Gen 2. Product package may still list USB 3.1 Gen 2.
  2. Cards shipped before April 2020 use ASM 1142 controller.
  3. The maximum Apple-supported OS for the Mac Pro 3,1 is OS X 10.11. Dosdude1 offers patchers to allow installation of newer versions of macOS for the Mac Pro 3,1. The Apple USB 3 driver in these patched newer versions will support the Allegro card. Note that performance may be limited by the Mac Pro 3,1 PCIe 1.1 slot bandwidth.
  4. Must use in slot 6 in Mac Pro 14,8.

Mac OS logoWindows logoPCI Express LogoRoHS Compliant logo