MSI DataMag 40Gbps review: Shiny, magnetic USB4 storage

Price When Reviewed

$170 for 1TB

Best Prices Today: MSI DataMag 40Gbps USB4 SSD

Magnetically attached SSDs can be handy, especially speedy 40Gbps models such as the MSI DataMag 40Gbps reviewed here. They can be fixed in place on any suitable metallic surface. Alas, that doesn’t include my aluminum Macs, but it does include the router right next to them.

What are the DataMag 40Gbps’s features?

Well, the name and intro give away part of the story — the magnetic ring on the back of the unit (see below) and that the drive is 40Gbs USB4. It measures a little over 2.5-inches across in both directions, is a little under 0.5-inches thick, and has a lanyard opening on the upper right. Weight is 2.8 ounces, which gives a nice solid heft.

The DataMag 40gbps sports a Phison U21 controller and stacked/layered/3D TLC (Triple-Level Cell/3-bit) NAND. The company warranties the drive for five years, or until the TBW rating is reached.

Said rating is 750TBW (terabytes that may be written) per one terabyte of capacity. That’s on the generous side for an external SSD. The norm is three years and 600TBW or less depending on the NAND involved.

How much is the MSI DataMag 40Gbps?

The DataMag 40Gbps is currently available in 1TB/$170 and 2TB/$296 capacities — those prices come from the company, which also promises that a 4TB version is on the way. Those are a tad pricey for USB4, but not outrageously so.

The drive also hasn’t shown up on Amazon as of this writing, so there may be discounts to be had in the near future.

How fast is the MSI DataMag 40Gbps?

Short answer: plenty fast, though there were areas where the drive didn’t quite match the competition. Part of the issue was undoubtedly that the drive MSI sent us is only 1TB, meaning it had exactly half the NAND to play with as the Adata SE920, and one-quarter the NAND of the top-rated LaCie Rugged SSD4.

Less NAND means less secondary cache and dropping to the NAND’s native write rate sooner. That said, the native write rate of around 830MBps will still get the job done in a suitable amount of time in many cases.

Less secondary cache or not, the DataMag 40Gbps was in no hurry to get to its native write rate. In fact, it actually delivered an outstanding queued sequential read score in CrystalDiskMark 8 before dropping off the pace.

The DataMag 40Gbps was also outstanding in the CrystalDiskMark 8 4K tests. Especially with multiple queues in play. Queues are not something a lot of software feature (Windows doesn’t), but…

It was in our real-world 48GB transfers that the DataMag 40Gbps began to lag a bit more. I wasn’t expecting this to take place with the small file and folder operations; usually a good CrystalDiskMark 8 4K score translates to a good performance with the smaller files and folders.

Being “only” a 1TB drive no doubt hurt the DataMag 40Gbps’s 450GB write time, which was twice that of the competition.

Here you can see where the lag in the 450GB write began. About 50GB in, the DataMag 40Gbps’s write speed dropped to USB 10Gbps levels, or around 830MBps.

If MSI had sent us the 2TB version of the DataMag 40Gbps, it undoubtedly would’ve done better in the real-world transfer tests.

Regardless, it offers a nice boost in sustained throughput over the soon-to-be-reviewed (but already tested) MSI DataMag 20Gbps, and other USB 3.2×2 (20Gbps) SSDs.

Should you buy the MSI DataMag 40Gbps?

I love the look, like the performance, and appreciate that magnetic attachment. Given competitive pricing I’d give it a nod, but as always — read our other reviews and shop around.

How we test

Drive tests currently utilize Windows 11 24H2, 64-bit running off of a PCIe 4.0 Samsung 990 Pro in an Asus Z890-Creator WiFi (PCIe 4.0/5.0) motherboard. The CPU is a Core Ultra i5 225 feeding/fed by two Crucial 64GB DDR5 5600MHz modules (128GB of memory total).

Both 20Gbps USB and Thunderbolt 5 are integrated into the motherboard and Intel CPU/GPU graphics are used. Internal PCIe 5.0 SSDs involved in testing are mounted in an Asus Hyper M.2 x16 Gen5 adapter card sitting in a PCIe 5.0 slot.

We run the CrystalDiskMark 8.04 (and 9), AS SSD 2, and ATTO 4 synthetic benchmarks (to keep article length down, we report only the first) to find the storage device’s potential performance. Then we run a series of 48GB transfer and 450GB write tests using Windows Explorer drag and drop to show what users will see during routine copy operations, as well as the far faster FastCopy run as administrator to show what’s possible.

A 25GBps two-SSD RAID 0 array on the aforementioned Asus Hyper M.2 x16 Gen5 is used as the second drive in our transfer tests. Formerly the 48GB tests were done with a RAM disk serving that purpose.

Each test is performed on a NTFS-formatted and newly TRIM’d drive so the results are optimal. Note that in normal use, as a drive fills up, performance may decrease due to less NAND for secondary caching, as well as other factors. This issue has abated somewhat with the current crop of SSDs utilizing more mature controllers and far faster, late-generation NAND.