Sonnet Twin25G T5 Dual-Port 25GbE Thunderbolt 5 Adapter with Two SFP28 Transceivers

If your post-production, broadcast, or bandwidth-heavy workflows have outgrown 10GbE, the Sonnet Twin25G T5 is the upgrade your setup has been waiting for. This compact Thunderbolt 5 adapter adds dual-port 25GbE optical networking to any Mac, Windows, or Linux machine — no PCIe slot required. It ships with two 25GBASE-SR SFP28 transceivers already installed, a Thunderbolt 5 cable, and a ThunderLok connector lock, so you have everything you need to hit the ground running. Powered by a Mellanox ConnectX controller with its own onboard processing, the Twin25G T5 handles TX/RX data independently — keeping CPU load low and throughput high. Whether you're connecting to a 25GbE switch, shared NAS storage, or directly to another 25GbE-enabled device, the adapter maintains consistent, low-latency performance. And with a second Thunderbolt 5 port built in, you're not sacrificing connectivity — you can daisy-chain additional Thunderbolt devices, connect a USB peripheral, or drive up to an 8K display from the same port. Key Features Dual-port 25GbE optical networking via Thunderbolt 5 — no PCIe slot needed Two 25GBASE-SR SFP28 transceivers included and pre-installed Backward compatible with 10GbE — integrate now, upgrade your switch later 80 Gbps Thunderbolt 5 interface — supports full dual-port bandwidth at maximum throughput Second Thunderbolt 5 port for daisy-chaining peripherals, USB devices, or connecting up to an 8K display Mellanox ConnectX controller with onboard processing — low CPU load, minimal latency Supports jumbo frames up to 9000 bytes, flow control, RSS, and TCP/UDP/IPv4 checksum offloading Temperature-controlled variable-speed fan — runs cool and nearly silent Compact desktop footprint — 3.0 x 11.6 x 5.9 in. (7.6 x 29.5 x 15 cm) Thunderbolt 5 cable and ThunderLok connector lock included 2-year product warranty with lifetime technical support What's in the Box Twin25G T5 Thunderbolt 5 Adapter Two 25GBASE-SR (short-range) SFP28 transceivers (pre-installed) Universal 60W power adapter (100–240V, 50–60Hz) Region-specific power cable 0.8-metre Thunderbolt 5 cable ThunderLok-A connector lock Documentation Does the Twin25G T5 work with older Thunderbolt ports — Thunderbolt 3 or 4? Yes. The adapter is backward compatible with Thunderbolt 3, 4, and USB4 ports. When connected to a Thunderbolt 4 or 3 computer, one 25GbE port runs at full bandwidth. Full dual-port performance requires a Thunderbolt 5 host port. Can I use this with my existing 10GbE infrastructure? Absolutely. The Twin25G T5 supports both 25 Gbps and 10 Gbps per port, so you can connect it to your existing 10GbE switch today and upgrade to a 25GbE switch when you're ready — no need to replace the adapter. Do I need to install a driver? Yes, a driver is required. On macOS, you'll configure the adapter via the Network control panel after installation. On Windows, use Device Manager. On Linux, configuration is done via the command line or a graphical utility. Can I connect a display to the second Thunderbolt 5 port? Yes. The secondary Thunderbolt 5 port supports connecting one display at up to 8K resolution, depending on what your computer supports. It also provides 15W of power for bus-powered Thunderbolt or USB devices. What fibre cabling do I need? The included SFP28 transceivers are 25GBASE-SR (short-range) modules for multi-mode fibre with LC connectors. For longer runs, Sonnet offers optional long-range SFP28 modules (Part No. G25E-SFP28-LR) for single-mode fibre. Specifications Part Number TWIN25G-T5 Form Factor Thunderbolt 5 25GbE adapter 25GbE Controller Mellanox ConnectX External Connectors Two Thunderbolt 5 ports (second port supports Thunderbolt peripheral, USB device, or display); two SFP28 sockets with two 25GBASE-SR optical transceivers; 12V power port Network Support 25 Gbps, 10 Gbps Data Rates per Port 25 Gbps, 10 Gbps Teaming / Link Aggregation Not supported Maximum Packet Size 9000 bytes (jumbo frames) Advanced Features Flow control, MSI, RSS (Receive-Side Scaling), Multicast filtering, 64-bit address support Wake-on-LAN Not supported Stateless Offloads TCP, UDP, and IPv4 checksum offloading; TRO (TCP Receive Offload) Power Adapter Universal 60W, 100–240V, 50–60Hz, NRTL Certified Operating Temperature 0°C to 35°C (32°F to 95°F) Dimensions — Adapter (WxDxH) 3.0 x 11.6 x 5.9 in. (7.6 x 29.5 x 15 cm) Dimensions — Power Adapter (WxDxH) 2.5 x 4.4 x 1.3 in. (6.4 x 11.2 x 3.3 cm) Weight — Adapter + Power Adapter 4.4 lbs. (2 kg) Weight — Complete Package 5.8 lbs. (2.63 kg) Compliance RoHS 3 (Directive 2015/863); IEC62368-1 and IEC62368-2 Safety Warranty 2 years Technical Support Lifetime Country of Origin United States Download Power Adapter Manual (PDF) Compatibility Mac macOS 15 (Sequoia) or later macOS Tahoe compatible Any Mac with Thunderbolt 5, Thunderbolt 4, Thunderbolt/USB4, or Thunderbolt 3 ports Compatible with all Apple M-series Macs and Intel Macs with Thunderbolt 3 Windows Windows 11 Computer with Thunderbolt 5, Thunderbolt 4, or USB4 ports Note: USB4 support requires a "USB4 Host Router (Microsoft)" — confirm via Device Manager under Universal Serial Bus controllers Linux Linux kernel 6.12, 6.18 or newer Computer with Thunderbolt 5, Thunderbolt 4, or USB4 ports