Oyen Digital U34 Bolt 4TB USB4 portable SSD

Capacity and interface

The Oyen Digital U34 Bolt is a 4 TB external SSD that connects through a USB-C port running USB4 at 40 Gbps. It uses an NVMe PCIe 4.0 x4 controller with TLC NAND flash to reach sequential speeds up to 2800 MB/s. The drive ships formatted in HFS+ for macOS and can be reformatted for other systems.

Practical limits of USB4 40 Gbps

The 2800 MB/s ceiling is only available when the host supplies a USB4 or Thunderbolt 3/4 connection with full 40 Gbps bandwidth. On older USB 3.2 or USB 3.1 ports the drive will fall back to the host's lower signalling rate, so sustained throughput drops accordingly. The ASMedia ASM2464PD bridge handles the protocol conversion, but total performance remains bound by the host link. Operating temperature range is 32 °F to 158 °F.

Upgrade path and when it matters

This drive replaces slower USB 3.x portable SSDs and mechanical external drives for workflows that move multi-gigabyte files such as 4K video, RAW photo libraries or large project archives. The 3000 TBW endurance rating supports heavy daily writes, and the MIL-STD-810F ruggedisation adds confidence for field use. Buyers whose hosts top out at 10 Gbps USB will not see the advertised speed and should consider whether the premium is justified.