Samsung Portable SSD P9 Review: USB4 Speed Meets High Pricing

Samsung’s first USB4 portable SSD makes its strongest case when a job involves writing large amounts of data. The 2TB P9 led the reviewed drives in a 50GB file copy and held write speeds well above many competitors during a long sequential test. It also fits a 40Gbps interface into a slim, travel-friendly shell. The catch is the price: the tested model costs $649, so the speed advantage needs to matter to your work.

The P9 is available in 1TB, 2TB, 4TB and 8TB capacities, with rated sequential reads up to 4,000 MB/s and writes up to 3,800 MB/s. Samsung lists prices of $339.99, $649.99, $1,439.99 and $2,879.99, respectively. At the time of the review, only the 2TB model was in stock. Those figures sit in a market where competing USB4 drives have become harder to find and prices have shifted upward. The P9 is expensive; its value depends partly on what alternatives are actually available when you buy.

A slimmer shell and a useful cable

At 3.5 by 2.6 by 0.3 inches and 0.21 pounds, the P9 is compact without being the smallest or lightest drive around. It’s thinner than Samsung’s T9, which measures 0.55 inches deep and uses a 20Gbps connection. The P9 trades the T9’s textured rubber coating for a rigid metal shell and a rubberized base that helps keep it from sliding across a desk.

Samsung lists a two-meter drop rating, but doesn’t provide dust or water resistance ratings. The drive feels solid in hand, though the visible seam around its base is a small design blemish. For a portable drive that may move between a desk and a camera bag, durability claims are useful only up to a point; the missing resistance ratings leave exposure to dust and moisture unspecified.

The bundled 16-inch braided USB-C cable is a welcome practical detail. Its length gives desktop users more flexibility than a short lead, and two hook-and-loop straps help manage slack. It’s the only substantial accessory in the box, but a good cable matters for a drive that depends on a high-speed connection to reach its advertised performance.

Magician offers useful controls, with a large interface

The drive includes a link to Samsung Magician, which prompts users to download the current software. The app provides drive health and temperature information, performance monitoring, diagnostics, secure erasing and encryption controls. The P9 supports 256-bit hardware encryption.

That’s a broad set of management features for an external SSD, though the desktop presentation feels oversized for the amount of information on screen. The reviewer found the health gauge particularly large when using a 65-inch TV as a monitor; switching to compact mode hides most of the interface. The controls may be useful for people who want to check drive condition or enable encryption, but the layout could use a more restrained desktop view.

Prices and alternatives depend on availability

Among the tested USB4 alternatives, SanDisk’s Extreme Pro was listed at $549 for 2TB, $100 below the P9. LaCie’s Rugged SSD4 had sold for $750 to $800 for 2TB at a few retailers, while Corsair’s EX400U was listed at $692. Both LaCie and Corsair models were increasingly difficult to find. The EX400U had previously stood out for its compact design, performance and price, but changing availability weakens the usefulness of its launch price as a comparison.

For less demanding transfer needs, the 2TB Crucial X10 was listed at $399. It uses a 20Gbps connection, half the bandwidth of USB4’s 40Gbps, and belongs to a lower performance tier. That difference can matter when moving large video projects or other files repeatedly; for routine backups or smaller transfers, the lower-cost option may be enough.

The test setup also matters when comparing results. The review used a Ryzen 7600X system with an Asus ROG Crosshair X870E Hero motherboard, which has native USB4 support. The drives were retested on that system, and the review switched to CrystalDiskMark 8 from version 7. The sustained-write Iometer test was the exception, so those results weren’t all produced under the same refreshed test conditions.

Fast transfers, with a strong sustained-write showing

In PCMark 10, which uses traces from applications and everyday tasks, the P9 placed behind LaCie and SanDisk USB4 drives as well as LaCie’s Thunderbolt 5 model. It did outperform Corsair’s EX400U. The result suggests that the P9’s headline sequential speeds don’t automatically translate into a top finish across mixed workloads.

In DiskBench, the reviewer copied a 50GB dataset containing 4,617 image, video and software ISO files to the drive, then copied it back after five minutes of idle time. The P9 led the group on the write portion. Its read result ranked fourth, but it still beat Corsair and came close to SanDisk. LaCie’s Thunderbolt 5 drive behaved unevenly on this USB4 test system, a reminder that host hardware and connection support can affect comparisons.

CrystalDiskMark produced the P9’s best result: first place for both reads and writes. This is a synthetic benchmark often used to represent best-case performance, and several high-end drives were close. SanDisk was a few hundred MB/s slower on reads but remained fast. Treat the result as evidence of the P9’s potential under favorable conditions, rather than a promise that every transfer will run at the same rate.

Long writes tell a more useful story for workloads that regularly fill a drive with footage or other large files. Like many SSDs, the P9 uses a fast write cache that absorbs incoming data; once that cache fills, performance can change. Samsung hasn’t disclosed the cache’s size, whether it varies by capacity, or whether it is fixed or dynamic. The review tested the 2TB model, so direct comparisons with larger drives carry that uncertainty.

During a 15-minute sequential-write run, the P9 started near 3,750 MB/s for about a minute. It then settled into a range of roughly 2,200 to 2,400 MB/s for about 12 minutes before dropping to 600–800 MB/s. In a longer 30-minute run, it returned to that middle range after about 17 minutes and held there through the end.

SanDisk’s Extreme Pro held roughly 3,500 MB/s for around three times as long at the start, then fell first to about 1,200 MB/s and later to around 800 MB/s, where it remained through the 30-minute test. Corsair’s EX400U was more consistent, but never exceeded 1,800 MB/s and often dipped below 1,600 MB/s. The P9’s unusual return to its faster middle range makes it stand out, though the undisclosed cache design leaves some detail unexplained.

A premium choice for workloads that use the speed

The P9 isn’t the clear winner in every test, but its write performance is a tangible advantage for people who move large files often. It beat Corsair’s EX400U consistently in the review, and its sustained-write results are especially strong once the initial cache period passes. The slim casing adds portability, while the 16-inch cable is a practical fit for desktop use.

At $649 for 2TB, it’s hard to recommend on speed alone to buyers who can use a 20Gbps drive or who find SanDisk’s $549 model in stock. The P9 looks like a better fit for creators and other users who can put its transfer performance to work and want a small USB4 drive. Its value will depend on how prices and availability settle across the category, and Samsung’s undisclosed cache details remain the main unanswered performance question.

For routine storage, the lower-cost alternatives offer a more sensible starting point. For repeated large writes, the P9’s speed profile makes its premium easier to justify.