Sonnet’s Echo Express SEL, the latest addition to the Echo Express line of Thunderbolt 2-to-PCIe expansion systems, is the smallest and quietest Echo chassis yet. It enables the use of a variety of high-performance PCI Express (PCIe) cards — originally designed for use in desktop computers — with any Mac with a Thunderbolt port.

The Echo Express SEL incorporates ultra-fast Thunderbolt 2 technology, which delivers twice the bandwidth of Thunderbolt and provides sufficient throughput to support many of the most demanding PCIe cards.

The new expansion chassis is suited for use with high-bandwidth networking cards, host bus adapters, and storage interface cards, allowing them to connect with Thunderbolt-enabled iMac, Mac mini, MacBook Air, and MacBook Pro computers, as well as Mac Pro computers that lack PCIe expansion slots. Plus, the Echo Express SEL’s dual Thunderbolt 2 ports not only support full-bandwidth connectivity with 20 Gb/sec Thunderbolt 2-equipped host computers, but provide full backward compatibility with 10 Gb/sec Thunderbolt-equipped computers and devices, and support daisy-chaining of other Thunderbolt 2 and Thunderbolt devices.

The Echo Express SEL supports low-profile, single-width PCIe 2.0 x8 cards. The majority of the most popular Thunderbolt-compatible 16Gb and 8Gb Fibre Channel, 10 Gigabit Ethernet, SAS and SATA host bus adapters, and RAID controller cards fall into this category.

Thunderbolt 2 technology is essential for enabling many high-performance cards, such as 10 Gigabit Ethernet, to yield optimal performance over Thunderbolt. For example, in a test using Small Tree Communications’ dual-port 10 Gigabit Ethernet CAT6 Network Adapter with the Echo Express SEL, performance increased by 40 percent compared to the same card tested in a standard 10 Gb/sec Thunderbolt-to-PCIe chassis. The list of compatible PCIe cards is available on Sonnet’s website, and is continually expanding as more cards are tested and certified.

Measuring 4 inches wide by 8.4 inches long by 2.8 inches tall and weighing just 1.75 pounds, the Echo Express SEL is compact and lightweight. It features a quiet, temperature-controlled fan to help keep even warm cards cool. When not needed, the fan slows down to a whisper.

The Echo Express SEL ships with an 80W external power adapter, keeping the system’s energy usage low. The SEL also conserves energy by automatically powering on whenever the connected computer powers on or wakes, or powering off when the computer powers off or sleeps. Sonnet includes a cable locking mechanism that secures the Thunderbolt connectors and prevents accidental cable disconnects.

The Echo Express SEL (part number ECHO-EXP-SEL) is now available for US$399 USD. More information on the product and compatible PCIe expansion cards is available at http://tinyurl.com/na5b6do .