Corsair EX400U: First benchmarks for the market launch of the fast USB4 SSD 16 comments
Image: Corsair
The EX400U external SSD with USB4 presented by Corsair at CES 2025 is released today. The compact but relatively heavy SSD reaches 4,000 MB/s read speed and clearly puts SSDs with USB 3.2 in the shade. Here are the first benchmarks, exact specifications and prices of the EX400U.
First tests with the Corsair EX400U
At this point you can’t see the full test, which won’t appear until next week for scheduling reasons. But here you can get a first impression of the direction these USB4 SSDs are heading.
And it’s pretty impressive: even at half power via USB 3.2 Gen 2×2 with 20 Gbps, the Corsair EX400U beats the entire team of external SSDs in the editorial test field in 3DMark Storage. If all performance is available via USB4 at 40 Gbit/s, which was the case here on the Thunderbolt 4 port compatible with a Core Ultra 9 285K, then even the Crucial P5 internal NVMe SSD with PCIe 3.0 is outperformed.
The obligatory verification of the manufacturer’s performance specifications confirms the promised 4,000 MB/s in sequential reading. However, the 3,600 MB/s mentioned above when writing hasn’t really come to fruition yet. This may depend on the platform. A detailed performance analysis, which also examines possible weaknesses, will follow shortly.
USB4 for your pocket
At 64.3 × 64 × 12 mm, the Corsair EX400U is significantly more compact than the Adata SE920 and the SanDisk Extreme Pro with USB4. For now, it’s the most compact USB4 SSD, but Adata has announced a successor, the SE940, which seems at least just as compact.
Corsair EX400U (Image: Corsair)
One gimmick on the Ex400U that Adata does not offer is MagSafe support. For example, the SSD can be magnetically locked to an iPhone with USB-C (iPhone 15 or newer). MagSafe can now also be used on Android smartphones with special cases. The USB4 SSD can be used directly on the smartphone as a fast storage expansion and can record high-resolution videos directly.
A real heavyweight
Although the dimensions are sufficient to fit in your pocket, the weight of 383 grams makes it heavy. This makes the EX400U more than twice as heavy as its less compact competitors. However, this should be beneficial for cooling. Details can be found in the following test.
Key data of the fastest external SSDs compared Corsair EX400U Adata SE920 SanDisk Extreme Pro LaCie Rugged Pro5 Form factor NVMe Internal dimensions (L × W × H) 64.3 × 64 × 12 mm 105 × 64.2 × 15.9 mm 140 × 68.7 × 11.9 mm 98 × 65 × 17 mm Weight 383 g 182 g 172 g 150 g Capacities 1 TB, 2 TB, 4 TB 2 TB, 4 TB Interface USB4 (40 Gbps) Thunderbolt 5 (80 Gbps) Connection USB Type-C to Type-C Max. transfer rate 4,000 MB/s read
3,600 MB/s write 3,800 MB/s read
3,700 MB/s write 6,700 MB/s read
5,300 MB/s write encryption k. A. Warranty 3 years 5 years Protection class k. A. IP65 IP68
Prices and availability
The EX400U can now be purchased in the Corsair store for around 165 euros (1 TB) and 240 euros (2 TB). The 4 TB version is currently not available, but is expected to cost 425 euros. Prices in online stores will likely be lower if there is widespread availability.
It’s even faster with Thunderbolt 5
But in terms of throughput, it’s even faster. The LaCie Rugged SSD Pro5 hits 6,700 MB/s, making it probably the fastest external SSD to date. Write speeds of up to 5,300 MB/s should be possible. After the 50 GB of cache, things deteriorate considerably: we can still expect a maximum of 5,000 MB/s read and 1,800 MB/s write, writes parent company Seagate. The Corsair EX400U 2TB always remains above 1 GB/s.
Enjoy blazing-fast read/write speeds of up to 6700 and 5300 MB/s with 50 GB cache, streamlining your workflow and increasing productivity for all creative projects. Without the cache, performance can reach 5000 MB/s read and 1800 MB/s write.
Seagate
The Thunderbolt 5 SSD is available from 405 euros (2 TB) or 564 euros (4 TB).
Topics: Corsair Flash Memory SSD USB4 Storage
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