This article covers StarTech PCIe外付けケース Thunderbolt 3接続 2x PCI Express 3.0 x16 8K 4Kビデオ出力 2TBT3-PCIE-ENCLOSURE.

Overview

StarTech.com brings a unique solution with the 2TBT3-PCIE-ENCLOSURE, an external PCIe expansion chassis designed for laptops and all-in-one PCs that lack internal expansion slots. By connecting over Thunderbolt 3 (or Thunderbolt 4), this enclosure adds two full PCIe 3.0 x16 slots to your system, enabling you to install capture cards, high-speed network adapters, NVMe drive adapters, FireWire cards, and more. It also includes a DisplayPort 1.4 output and a Thunderbolt 3 port for video daisy-chaining, supporting up to 8K/5K 60Hz or dual 4K 60Hz displays. This is not a typical eGPU box — it is a multi-purpose expansion chassis with flexible power delivery and active cooling. With a total bandwidth of 32Gbps (up to 21.6Gbps per slot), it allows reasonably fast data transfer for most expansion cards. The bundled 1-meter Thunderbolt 3 cable and universal power adapter (120W, with region-specific plugs) make it easy to set up out of the box.

Connectivity & Compatibility

Connectivity is straightforward: one Thunderbolt 3 (USB-C) port on the chassis connects to your host computer. The chassis itself provides two PCIe 3.0 x16 slots (electrical x16) for add-in cards. It also offers dual 12V 15W SATA power ports, enabling you to power additional devices like SATA SSDs or fan controllers directly from the enclosure. The active cooling fan keeps internal temperatures in check even under sustained load. The chassis is compatible with Thunderbolt 3 and Thunderbolt 4 hosts on macOS, Windows, and Linux — no driver installation required. It also supports daisy-chaining of multiple Thunderbolt 3/4 devices, which is handy if you already use a Thunderbolt dock or monitor. However, remember that the maximum card length is 20.3 cm (8 inches), and cards must be single-width. Most video capture cards, 10GbE NICs, and M.2 adapters fit well, but large gaming GPUs will not.

Product Info

The StarTech.com 2TBT3-PCIE-ENCLOSURE was released in the second half of 2023. It typically retails around ¥83,000 in Japan and $550 in the US. The package includes the chassis, a 1m Thunderbolt 3 cable, a 120W (12V 10A) power adapter, and four region-specific AC cords (US/Japan, UK, EU, AU/NZ). The warranty is two years from the manufacturer. Positioned in the mid-to-high end of the Thunderbolt expansion chassis market, this unit stands out by offering two full PCIe slots and 8K video output simultaneously. Competing products often focus on single-slot eGPU usage or lack video passthrough capabilities, giving this StarTech model a unique appeal.

Best Use Cases

Creative professionals and streamers are the primary target audience. You can install a high-end video capture card in one slot and an NVMe SSD adapter in the other, turning your lightweight laptop into a broadcast-ready workstation without sacrificing portability. Network engineers and IT administrators will appreciate the ability to add a 10GbE or 25GbE NIC to a laptop for lab work or on-site network diagnostics. Each slot delivers up to 25W of power, which is enough for most multi-gigabit network cards. Researchers and developers who need to test FPGA accelerator cards or AI inference modules on the go can use this chassis as a portable test bench. It avoids the need to dedicate a full desktop to experimentation. ## Alternatives
Razer Core X and Sonnet eGFX Breakaway Box are popular alternatives, but they are designed primarily for single graphics cards and usually lack video output ports. They also tend to be larger and more expensive. If you only need to connect a single GPU for gaming, those are better choices. On the budget side, J5Create and Plugable offer smaller, single-slot Thunderbolt 3 / USB4 expansion enclosures at lower prices. However, they often have lower power budgets and no DisplayPort output. For users who need two slots and 8K video, the 2TBT3-PCIE-ENCLOSURE is a more robust solution despite its shorter card length limit.

Things to Consider

The most critical limitation is card length: only up to 20.3 cm (single-width) cards will fit. If you plan to install a full-length GPU or a large compute accelerator, this chassis is not suitable. Always measure your cards before purchasing. Another consideration is Thunderbolt host requirement. Your computer must have a Thunderbolt 3 or 4 port to use this enclosure. USB-C ports without Thunderbolt support will not work. This is especially important for AMD-based laptops, which sometimes omit Thunderbolt. Bandwidth is also shared between the two slots — the total throughput is 32 Gbps, not per-slot. Running two high-bandwidth cards simultaneously (e.g., two NVMe adapters) will divide the available bandwidth. For most capture/NIC use cases, this is fine, but it's worth noting for power users. Finally, the 120W power adapter provides up to 25W per PCIe slot and another 40W via the SATA power ports combined

Product Disclosure (Amazon)

  • Manufacturer: StarTech.com(スターテック)
  • Seller: Startech Japan KK
  • Fulfilled by: Amazon
  • ASIN: B0CKBZGTSH
  • Note: This article covers a manufacturer-made product based on Amazon listing details.