Creatively Expandable
Echo III Rackmount
3-slot Rackmount Thunderbolt to PCIe Card Expansion System for Computers with Thunderbolt 4 or Thunderbolt 3 Ports
Sonnet Echo III Rackmount
Creatively Expandable
Echo III Rackmount
3-slot Rackmount Thunderbolt to PCIe Card Expansion System for Computers with Thunderbolt 4 or Thunderbolt 3 Ports
Sonnet Echo III Rackmount
Thunderbolt 3 Mac Computers

Connect Three Full-length PCIe Cards to Computers with Thunderbolt 4 or Thunderbolt 3 Ports

The best portable, mini desktop and all-in-one computers feature powerful CPUs and include high-performance Thunderbolt™ ports to support peripherals. But they lack the PCIe expansion slots creative pros need to install specialty adapter cards that enable their workflows by adding video and audio inputs, transcoding data, and connecting to high-speed shared storage and networks. Sonnet has a Thunderbolt solution — the Echo™ III Rackmount — a professional Thunderbolt to PCIe card expansion system. Via a single cable, connect three (up to) full-length (12.28 inches long) PCIe cards at the same time to your Mac®, Windows®, or Linux® computer with Thunderbolt 4 or Thunderbolt 3 ports.

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iMac Pro Thunderbolt 3 Ports
Avid HDX, AJA Kona 5 & Sonnet Fusion Dual 2.5" SSD PCIe Cards

Supports Every Thunderbolt Compatible, Non-GPU PCIe Card

Video PCIe Card IconAudio PCIe Card IconSAS/SATA PCIe Card IconNetworking PCIe Card IconSSD PCIe Card Icon

Echo III Rackmount supports every Thunderbolt compatible, non-GPU PCIe 4.0, 3.0, 2.0, and 1.1 card available including video capture and transcoding; audio DSP; 6Gb or 12Gb SAS or SATA host bus adapter; 10Gb or 25Gb Ethernet; SSD storage; and other specialty types to your system.

Do you have a card in mind but aren’t sure it’s compatible? We’ve put together a compatibility list that identifies cards conforming to Thunderbolt technology requirements, and organized by fit and power compatibility with specific expansion systems. 

PCIe Cards Compatibility PDF
Sound Mixer
Sound Mixer
Avid Pro Tools Qualified
Ready for up to Three Pro Tools | HDX PCIe Cards – no Extra Parts Required

At the flick of a switch, the Avid qualified Echo III Rackmount system is instantly optimized to support up to three Pro Tools | HDX PCIe cards, with no extra parts necessary! This chassis has been tested and is qualified by Avid Audio group for use with Avid Pro Tools HD 2020 software, and Avid Pro Tools HDX and HD Native systems.

Avid Cards Installed In Sonnet Echo III Rackmount

Avid Pro Tools | HDX cards sold separately

Sonnet Echo III Rackmount Installed in Mobile Rack Kit

Your Entire Multi-card Pro Tools | HDX System in 4U Rack Space

Sonnet makes it easy to integrate a complete 2- or 3-card Pro Tools | HDX system and a Mac mini® in just 4U of rack space. With the rugged 1U RackMac mini rackmount enclosure plus the 2U Echo III Rackmount you can combine the power of HDX with any Avid Pro Tools hardware I/O for a complete system, including the exciting Pro Tools | MTRX Studio all-in-one audio interface.

Avid Pro Tools | MTRX Studio, Sonnet RackMac mini, PCIe cards, and mobile rack kit sold separately

Media Composer Icon

Avid Media Composer Qualified

Echo III Rackmount is separately qualified by the Avid Video group for use with Avid Media Composer/Symphony with many current and older Mac computers with Thunderbolt 3 and Thunderbolt 2 ports.

Sonnet Echo III Rackmount Front View
Ready for Additional Expansion

Key Features

Adds Connectivity and Capabilities Icon

Adds Connectivity & Capabilities

Connects up to three high-performance non-GPU PCIe cards to your computer lacking expansion slots via a Thunderbolt cable.

Avid Pro Tools | HDX Compatible Icon

Avid Pro Tools | HDX Compatible

HDX compatibility mode enables use of up to three Pro Tools | HDX PCIe cards with no additional parts needed.

Broad PCIe Card Compatibility Icon

Broad PCIe Card Compatibility

Every Thunderbolt compatible, non-GPU card supported regardless of length or height.

Three PCIe Slots Icon

Three PCIe 3.0 Slots

One x16 plus two x8 slots support three full-height, single-width cards, or one double-width card plus one single-width card.

Pro Power Icon

Pro Power

Integrated 400W power supply with 75W auxiliary power. Saves energy by powering on/off automatically with the computer.

Remarkably Quiet Icon

Remarkably Quiet

Dual temperature-controlled, variable-speed Noctua fans rated at 17dBA automatically and quietly cool the cards.

40Gbps Thunderbolt System Icon

40Gbps Thunderbolt System

Offers full PCIe bandwidth for the installed cards. Learn more about Thunderbolt 3 performance benefits over Thunderbolt 4.

Two Thunderbolt Ports Icon

Two Thunderbolt Ports

One port connects to computer; second port supports daisy-chaining of up to five additional Thunderbolt peripheral devices.

Rugged 2U Steel Rackmount Housing Icon

Rugged 2U Steel Rackmount Housing + Optional Expansion Space

Provides robust and secure protection in server and DIT racks; space for an additional DuoModo Module (sold separately).

Apple M Series Compatible Icon

Apple® M series Compatible

Supports M series Macs (with PCIe cards that have compatible drivers).

Intel Mac and Windows Compatible Icon

Intel® Mac & Windows Compatible

Supports Intel Macs with Thunderbolt 3 ports and Thunderbolt 2 ports (with adapter and Thunderbolt 2 cable, both sold separately); and Windows 10 computers with Thunderbolt 3 ports.

Linux Compatible Icon

Linux Compatible

Supports Linux computers with Thunderbolt 4 and Thunderbolt 3 ports.

Free Lifetime Tech Support
Sonnet Echo III Rackmount Module & Chassis

Three PCIe 3.0 Slots Plus Power to Spare

The Echo III Rackmount features one x16 and two x8 PCIe 3.0 slots, enabling it to support a wide variety of cards at the same time. It integrates a universal 400W power supply, plus a 75W auxiliary power connector to support especially power-hungry non-GPU cards, including the Avid Pro Tools | HDX. The Echo III was designed without a power switch, because it powers on and off automatically with the connected computer, saving energy in the long run. With no power switch, you can’t forget to turn off the system!

Sonnet Echo III Rackmount Interior
Full-length PCIe Card Illustration
Low-profile PCIe Card Illustration
75W Auxiliary Power Connections Illustration
Sonnet Echo III R Interior Cooling

Built for Cool, Rackable Expansion

The Echo III Rackmount mounts in a rack space 2U tall, and is only 16.5 inches deep, making it ideal for use in a wide range of popular mobile racks, carts, and rack cases, and in server rooms as well. Its enclosure is formed of heavy-duty steel to provide secure mounting for the Echo III module and protection for the PCIe cards installed inside, and to support maximum airflow for cooling, regardless of where you install it in a rack.

Sonnet Echo III Rackmount with PCIe CardsSonnet Echo III Rackmount with Avid Cards
Echo III Rackmount accommodates the PCIe cards you need for your workflow, ranging from the largest video I/O and audio transcoding cards, to the smallest Ethernet NIC and USB interface cards
Sonnet Echo III Rackmount Installed in Rack Rails

Rack Steady

The Echo III Rackmount’s included adjustable rackmount extension rails enable the 2U enclosure to be installed securely in a variety of racks from 16 to 24 inches deep.

Noctua FanNoctua Fan
Rated 17.1 dBA Icon

Dual Fans. Ultra-quiet Operation.

Featuring dual Noctua fans, the Echo III Rackmount is designed to deliver ultra-quiet operation so that it can be comfortably used in noise-sensitive environments. Rated at 17.1dBA — below the 20dBA ceiling prescribed for use in recording and broadcast studios — the fans spread their noise spectrum to minimize any single frequency’s impact. To further ensure negligible noise levels, the fans are temperature-controlled, automatically speeding up and slowing down smoothly as needed, and the enclosure is engineered to optimize airflow over the installed cards to effectively and efficiently cool the system.

Noise Levels Comparison Chart
Comparative examples of noise levels source:

The Secure Connection for High Performance

40Gbps Thunderbolt Cable and ThunderLok 3 Included

Sonnet includes a Thunderbolt cable that supports Thunderbolt’s full 40Gbps bandwidth, and is fully compatible with Thunderbolt 4 and Thunderbolt 3 computers. Sonnet also provides a ThunderLok™ 3 Thunderbolt connector retainer clip that prevents accidental cable disconnections — just slide it over one end of the cable, and then plug in the connector and secure it to the chassis by turning a thumbscrew. Because of its unique design, ThunderLok remains on the cable so it won’t get lost when not in use.

Thunderbolt Cable with ThunderLok 3Supports Full 40Gbps Thunderbolt Bandwidth Icon
Thunderbolt Port with ThunderLok Mounting Hole
ThunderLok Advantage
Sonnet Thunderbolt expansion systems are designed with Thunderbolt ports that include a threaded mounting holes for securing Sonnet’s ThunderLok retainer clips that prevent accidental cable disconnections.
Thunderbolt Optical Cables Installation Illustration

Get Full Thunderbolt Performance, at a Distance

Whether noisy PCIe card fans make it impractical to use the Echo III Rackmount in a noise-sensitive environment, or because securing it in another room is required, you may find it necessary to put some space between the chassis and computer. No problem! Thunderbolt optical cables (sold separately), available in lengths from 5 to 50 meters, enable you to locate your equipment where you need and connect the pieces without loss of functionality. These thin, lightweight, and tough fiber optic cables are easy to route, and support high-speed data transmission equal to copper Thunderbolt cables.

Thunderbolt Optical Cables

40Gbps Thunderbolt

Fastest External Interface Available

The Echo III Rackmount features a 40Gbps Thunderbolt interface that delivers up to 2800 MB/s of PCIe bandwidth, enabling it to support 4K video capture and processing cards at high frame rates, audio DSPs, and 25GbE and dual-port 10GbE network cards at full performance.

Thunderbolt 40Gbps Ports Icons
Dual 40Gbps Thunderbolt Ports
One port is reserved for the connection to your Thunderbolt 4 or Thunderbolt 3 computer; the second port enables expansion of up to five additional Thunderbolt peripheral devices in a daisy chain.
10Gbps USB 3.1 Gen 2 Icon
10Gbps USB 3.2 Gen 2 Support
10Gbps USB 3.2 Gen 2 support allows you to connect a USB device to the second Thunderbolt port using the proper cable or adapter.
15W Power Icon
Provides 15W of Power
For peripherals requiring extra power, 15 watts is provided to bus-powered devices.
4K & 5K Display Icon
Supports Connecting One 5K 60Hz Display
Maximize the utilization of one computer Thunderbolt port.
Thunderbolt 4 Computers

Compatible with Thunderbolt 4 Computers and Apple M series Macs

Echo III Rackmount is fully compatible with Thunderbolt 4 computers, including Apple M series Macs. Sonnet Thunderbolt expansion systems are purposely designed with a Thunderbolt 3 controller and its four lanes of PCIe (not available in a Thunderbolt 4 peripheral) to achieve maximum simultaneous ingest speeds. Learn more about the performance benefits of Thunderbolt 3 over Thunderbolt 4.
Apple M Series CPU

Compatible with Apple M Series Macs

see Tech Specs for details

Older Macs with Thunderbolt 2 Ports

Backward Compatible with Older Macs

No Thunderbolt 4 or Thunderbolt 3? No problem — the Echo III Rackmount is also compatible with Macs with Thunderbolt 2 or Thunderbolt ports when used with the bi-directional Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter and a Thunderbolt cable (both sold separately).
Sonnet Echo III Desktop

Desktop Version Available

Choose between the Echo III Rackmount and Echo III Desktop to suit your workflow needs. The Echo III Desktop is wrapped in a rugged, yet lightweight aluminum outer shell, resulting in a system light enough to carry without weighing you down, yet sturdy enough to securely protect the installed PCIe cards.

Sonnet DuoModo Family

Part of the DuoModo Family

The heart of the Echo III Rackmount – the Echo III Module – is part of Sonnet’s DuoModo™ family of modular Thunderbolt expansion systems, comprising of interchangeable modules for PCIe cards and eGPU card expansion, a Mac mini mounting system (with integrated 40Gbps Thunderbolt storage dock), and desktop and rackmount enclosures so you can quickly and easily interchange modules depending on your workflow.

Learn More
Learn why Sonnet’s Pro Products Rely on Thunderbolt 3 Technology for Maximum Performance

Echo III Rackmount