MSI DataMag 40Gbps USB4 SSD Review: Fast, But Not the Fastest

February 13, 2026 Rachel Kim – Technology Editor Technology

MSI has released the DataMag 40Gbps, a portable solid-state drive featuring a magnetic attachment system and USB4 connectivity. The drive, available in 1TB and 2TB capacities, aims to provide fast data transfer speeds and convenient portability for tech enthusiasts and creative professionals.

The DataMag 40Gbps boasts sequential read speeds up to 4000MB/s and write speeds of 3600MB/s, positioning it among the faster external SSD options currently available, though testing by PCWorld revealed it to be the slowest USB4 SSD tested, with speeds dropping to 10Gbps during extended writes. The drive utilizes a Phison U21 controller and 3D TLC NAND flash memory. A 4TB version is planned for release.

A key feature of the DataMag 40Gbps is its magnetic attachment system. Included metal rings allow the drive to securely attach to compatible laptops, tablets, or smartphones. This design intends to reduce cable strain and provide a stable connection during data transfers. A lanyard opening is likewise included for portability. The drive measures a little over 2.5 inches in both directions and is under 0.5 inches thick, weighing 2.8 ounces.

MSI offers a five-year warranty on the DataMag 40Gbps, or until the TBW (terabytes written) rating is reached. The 1TB model has a TBW rating of 750TB, which is considered generous compared to the typical three-year warranty and 600TBW or less offered on many external SSDs.

Currently, the 1TB DataMag 40Gbps is priced at $170, while the 2TB model costs $296. The drive has not yet appeared on Amazon, potentially indicating future discounts may develop into available. Testing revealed that the 1TB model experienced performance limitations during real-world 48GB transfers, with write speeds dropping to USB 10Gbps levels after approximately 50GB of data was transferred. A 2TB model is expected to perform better in these scenarios.

The DataMag 40Gbps is compatible with iPhone Pro models that support ProRes video recording, offering a reliable storage solution for high-quality footage. The 4TB model can reportedly hold up to 143 minutes of 4K/120fps video.