Adata has announced its new SE920 external SSD, the company's first external drive with a USB4 interface. The drive promises an up to 4000 MB/s sequential read speed (with SLC caching and when working with a USB4 host), which makes it one of the industry's fastest external storage device designed for consumers. In fact, it is even going to outperform any external SSD with USB 3.x or Thunderbolt 3/4 interface as far as a sequential read speed is concerned.
Adata will offer its SE920-series drives in different versions featuring different capacities, yet for now the company has kept details about the family confidential. Adata also hasn't talked about the architecture of its SE920 drive (which SSD controller it uses, how high is the write speed, etc.), though it says that the SSD uses the company's proprietary Heat Conduction technology that ensures appropriate cooling and consistent performance.
Designed to compete with the best external hard drives and SSDs, Adata's SE920 drives will be among the fastest portable storage devices with a Thunderbolt 3/4 and USB4 interface when they are available later this year. This is not particularly surprising as most of external storage devices with a TB3 interface integrate a previous-generation SSD with a PCIe Gen3 interface that cannot even theoretically saturate a TB3 bus (which supports non-video bandwidth of up to 32.4 Gbps, or 4.05 GB/s).
Furthermore, since TB3 uses an 8b/10b encoding with a rather high overhead, its actual usable bandwidth is about 25.92 Gbps or 3.24 GBps. By contrast, even an entry-level drive with a PCIe 4.0 x4 interface can easily hit a 4 GBps throughput. Meanwhile, USB4's 128b/132b encoding ensures that the interface's usable bandwidth is considerably closer to the theoretical one as this method has a lower overhead.
Typically, high-performance external SSDs pack an M.2 drive with a PCIe / NVMe interface as well as a PCIe-to-USB bridge. If this is the case with the SE920, then the drive integrates an NVMe M.2 SSD, a PCIe-to-USB4 bridge, and a USB4 chip responsible for power delivery support and orientation of the connector. Meanwhile, it is possible that Adata developed its SE920 from scratch and did not just repurpose a fast drive with a PCIe interface.
Adata has not announced pricing of its SE920 external SSDs with a USB4 interface, but we can assume that these drives are going to be premium products.
