TechRadar Verdict
Another 20Gbps portable SSD that proves magnetic mounting is a convenience worth having. It isn’t as quick as native USB4 models but it’s sturdier than most plastic rivals and it keeps cool under load. Though it's a shame it can be hard to find for a decent price in some regions.
Pros
- +
Excellent performance
- +
Magnetic attachment
- +
Tough design
Cons
- -
Metal shell can scratch other devices
- -
Not full USB4 speeds
- -
Availability varies
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MSI Datamag: 30-second review
The MSI Datamag is a rare portable SSD that combines real-world speed with a genuinely useful design twist. The 20Gbps USB 3.2 Gen 2x2 interface keeps transfers moving fast and in testing the drive very comfortably met and exceeded its rated read and write speeds.
It’s quick to launch projects, back up big shoots and handle transfer tasks without fuss and is a notable step above 10Gbps rivals that top out under 1,000MB/s.
The standout feature is the magnetic mount. Snap it to an iPhone or any MagSafe-compatible case or use the included stick-on rings to park it on laptops, rigs or consoles. Cable management is easy thanks to the included short and long USB-C leads plus a USB-C to USB-A adapter for older gear.
The compact square shell uses aluminum as a heat spreader and the finned edges help the drive stay cool in sustained work. In extended stress runs I saw consistent throughput and no throttling.
Two quick caveats: you need a USB 3.2 Gen 2x2 port for full speed and there’s no stated IP rating, so treat it as a tough metal portable drive rather than a truly ruggedized model.
Price and availability vary by region but it generally compares well for the performance on offer – especially considering the five-year warranty that adds some extra peace of mind.
If you want a compact fast drive that mounts neatly on a phone or workstation without extra fuss, the Datamag is an easy pick for everyday use. You can pay more for flagship USB4 drives that are a shade quicker or spend less on 10Gbps options but few match the overall blend of speed, thermals and magnetic attachment convenience.
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MSI Datamag: Pricing and availability
- How much does it cost? 2TB: $160 / £160 / AU$269
- When is it out? Available now
- Where can you get it? Available in most major markets including the US, UK and Australia
The MSI Datamag 20Gbps isn’t always stocked at all retailers, so start with your local MSI website and its Where to Buy page or check your country’s authorized retail partners for current options.
It’s generally easier to find in Australia and the UK while US availability varies by capacity and retailer.
In the MagSafe-friendly portable SSD niche there are only a few direct rivals and among 20Gbps-class drives the Datamag is competitive, but some almost as fast models do undercut it on price.
- Value: 4 / 5
MSI Datamag: Specs
Model No. | S78-440Q870-P83 |
Controller | Phison PS2251-U18 |
Capacities | 1TB / 2TB / 4TB |
Capacity tested | 2TB |
Tested sequential performance (Read/Write) | 1642 / 1514 MB/s |
Connection | USB 3.2 Gen 2x2 (20Gbps) on USB-C |
IP Rating | None |
Dimensions | 66 x 66 x 13 mm (W x H x D) |
Weight | 81g |
Power source | USB-bus power |
Warranty | 5-year limited warranty |
MSI Datamag: Design
- MagSafe compatible
- USB-C with USB-A adapter
- Aluminum heatsink
The Datamag looks and feels purpose-built rather than being just another generic plastic-wrapped portable SSD. MSI uses a compact square footprint with trimmed corners and a radial brushed top that keeps fingerprints in check and gives the logo a low-key finish.
The aluminum enclosure doubles as a heat spreader and the ribbed edge detailing is more than cosmetic, helping the drive shed heat during long writes. It’s a tidy pocketable shape that doesn’t snag cables in a bag and the single USB-C port sits flush so it’s easy to pack.
The headline design trick is the magnetic mounting system. On an iPhone or any MagSafe compatabile phone (and that now includes the Pixel 10 thanks to Pixelsnap) it snaps on securely and for non-magnetic surfaces MSI includes two stick-on metal rings in black and white. That makes the Datamag handy on varied rigs, claptops, consoles and other devices since you can park it exactly where you want it and keep the cable strain-free.
MSI also bundles both long and short USB-C cables plus a USB-C to USB-A adapter, so you can go access it on older devices, or just have a bit of versatility when you run out of ports. The lanyard loop in the corner is a small but smart touch for tethering for extra security.
At 66 x 66 x 13mm (2.60 x 2.60 x 0.51 inches) and 81g (0.179lb), the Datamag carries a reassuring heft without feeling bulky. The square puck format spreads weight across a phone well, so it stays put during handheld shooting and the rounded edges keep it comfortable against a palm.
There’s no stated IP rating, so treat it as a solid metal portable rather than a true rugged drive. Overall the design is simple, durable and very practical.


- Design: 4 / 5
MSI Datamag: Performance
- Great performance
- No throttling
Rated sequential read | 1600 MB/s |
Rated sequential write | 1500 MB/s |
ATTO peak read | 1660 MB/s |
ATTO peak write | 1860 MB/s |
Sustained read in Windows | 1642 MB/s |
Sustained write in Windows | 1514 MB/s |
Thermal throttling in 30-minute read/write test | None |
Aside from magnetic wizardry, performance is the Datamag’s calling card and the 20Gbps USB interface and Phison PS2251-U18 controller deliver impressive throughput.
In the ATTO benchmark I saw peaks of 1,660MB/s reads and 1,860MB/s writes, while sustained transfers in Windows managed 1,642MB/s read and 1,514MB/s write. That’s comfortably above the rated 1,600 / 1,500MB/s and well ahead of 10Gbps rivals like the SanDisk Extreme and Samsung T7 that top out near 1,000MB/s. In comparison, higher-tier 20Gbps options such as the SanDisk Extreme Pro can read a touch faster at around 1,900MB/s and of course USB4 drives are even faster.
The aluminum body with finned edges helped keep temps in check and I saw no throttling in a 30-minute mixed read and write run. For large media copies, camera offloads and scratch disk use the Datamag feels snappy and dependable under load.
- Performance: 4.5 / 5
MSI Datamag: Final verdict
MSI’s Datamag is a portable SSD that feels ready for real-world workloads. It’s fast in everyday tasks, doesn’t slow down on long transfers and stays cool thanks to the metal shell.
The square pocketable design is easy to carry every day and the magnetic mount and included rings make it quick to attach to a phone or other equipment.
Pricing is decent for the class and the five-year warranty is a great bonus. If you want speed with a smart attachment system, the Datamag delivers dependable 20Gbps performance in a compact easy-to-mount package.
Should I buy the MSI Datamag?
Value | Well priced considering the features | 4.5 / 5 |
Design | Sturdy metal build with magnetic attachment | 4 / 5 |
Performance | Excellent read / write speeds with no throttling | 4.5 / 5 |
Overall | A very unique and handy drive with performance to match | 4.5 / 5 |
Buy it if...
You’ll use the magnetic mount
There are cheaper options if MagSafe compatibility isn’t a key need in your usage.
Your device has a USB 3.2 Gen 2x2 port
To get the full speed of the Datamag you need a modern device with a fast 20Gbps USB port.
Don't buy it if...
You need absolute top-end speeds
The MSI Datamag is fast but there are even quicker drives if you need bleeding-edge performance.
You want a soft-touch drive
The Datamag has a tough aluminum shell and can scratch other gear if left loose in the same bag.
Also consider
Corsair EX400U
A faster alternative from Corsair, the EX400U is an excellent choice for those wanting USB4 performance plus MagSafe compatibility.
Read our full Corsair EX400U review
Ugreen 40Gbps M.2 Enclosure
This flexible option means you can drop in your own M.2 NVMe drive (2230, 2242 or 2280) and convert it into a fast USB4 external drive.
Read our full Ugreen 40Gbps M.2 Enclosure review
For more options, we've tested out the fastest external SSDs you can get right now.

Lindsay is an Australian tech journalist who loves nothing more than rigorous product testing and benchmarking. He is especially passionate about portable computing, doing deep dives into the USB-C specification or getting hands on with energy storage, from power banks to off grid systems. In his spare time Lindsay is usually found tinkering with an endless array of projects or exploring the many waterways around Sydney.
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