The RackMac mini. Image credit: Sonnet
Continuing its almost 30-year legacy of Mac expansion, Sonnet’s new Thunderbolt 5 hardware transforms Apple’s Mac mini into a rack-mounted workstation with high-speed PCI-e.
Sonnet Technologies is expanding the power and flexibility of the Mac mini with new professional hardware built for Apple’s latest M4 and M4 Pro models. At NAB 2025, the company introduced a rackmount enclosure, a modular PCI-e expansion system, and a next-generation external GPU chassis.
xMac mini: modular PCIe expansion system
The xMac mini Expansion Module is a 2U rackmount system that houses one or two Mac minis and connects them to high-performance PCI-e cards using Thunderbolt. It’s built for demanding use cases like media ingest, networking, and SSD storage, with options to pair the system with Sonnet’s Echo II DV or Echo III expansion modules.
The system allows users to install high-performance PCI-e cards — including digital video interfaces, NVMe SSD storage, and 25Gb Ethernet adapters — and connect them to a Mac mini via Thunderbolt 4 or Thunderbolt 5.
The xMac mini. Image credit: Sonnet
Sonnet will offer several PCI-e expansion modules for the system. The Echo II DV module supports two PCI-e cards and connects via dual Thunderbolt cables for full bandwidth to each slot.
A new Thunderbolt 5 version will double that throughput when paired with compatible Macs. For users who need more connectivity through a single cable, the Echo III module supports three PCI-e cards and includes a built-in bridge that intelligently splits bandwidth across all slots.
Compared to the earlier xMac mini Server systems, which were limited to a single Mac and slower PCI-e connectivity, the latest version supports multiple configurations and embraces Thunderbolt 5 speeds.
RackMac mini: high-density rackmount solution
The RackMac mini (2024+) is a rugged steel enclosure that houses up to three Mac mini units side by side in a standard 19-inch rack. Its 2U design features front-to-back airflow, front panel access to power buttons and USB-A ports, and additional internal space for USB SSDs.
Its 5.2-inch mounting depth makes it ideal for mobile racks, edit bays, or server deployments.
Sonnet positions the RackMac mini as a space-efficient solution for pro workflows, offering physical security and cable management for Mac minis used in production environments.
eGPU Breakaway Box 850e: Thunderbolt 5 PCI-e breakout box
The Breakaway Box 850e is a Thunderbolt 5 PCI-e enclosure designed for use with full-length, full-height PCI-e cards. While it carries the “eGPU” name, macOS has no support for external graphics cards on Apple Silicon. Regardless, it can still be used for PCI-e expansion for Mac mini and Mac Studio.
Sonnet’s new enclosure offers up to 6,000 MB/s of PCI-e bandwidth for high-performance cards like digital video I/O, NVMe SSDs, or multiport network adapters. It’s still in preview, but represents a new class of Thunderbolt enclosure aimed at professionals who need fast, reliable PCIe access without moving to a Mac Studio or Mac Pro.
The 850e is particularly useful for workflows that benefit from high-bandwidth PCI-e cards but don’t rely on GPU acceleration — such as real-time video capture, AI accelerators, or ultra-fast storage arrays.
Pricing and availability
The xMac mini Expansion Module is priced at $499.99 and is currently in stock. It securely houses a Mac mini within a DuoModo desktop or rackmount enclosure and includes a built-in 40Gbps Thunderbolt 3 storage dock for NVMe storage expansion and additional peripheral ports.
The RackMac mini (2024+) Enclosure is available for $299.99 but is currently out of stock. It houses up to three Mac mini units in a 2U rackmount chassis with front-to-back airflow and front panel access to ports and power buttons.
Sonnet hasn’t yet announced pricing or a ship date for the Breakaway Box 850e.
Sonnet’s new lineup gives Mac mini users the kind of modular power and flexibility once reserved for much larger systems, and positions the mini as a serious contender in modern pro workflows.
