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Corsair
Model: CSSD-EX400U-1TB
| Capacity | 1TB |
| Interface | USB4 |
| Form Factor | External |
| Read Speed | 3,300 MB/s |
| Write Speed | 3,000 MB/s |
| Endurance (TBW) | 600 TB |
| Warranty | 5 Years |
A USB4 portable from Corsair with 3300 MB/s read on Thunderbolt 4 / USB4 hosts - and the full 5-year warranty. The EX400U 1TB portable is a competitive USB4 entry point for video editors who need Thunderbolt-class speeds without the LaCie price tag.
See how it stacks up against competitors in our High-Speed Portable SSDs SSD comparison, or browse related SSD buying guides.
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The Corsair Corsair EX400U Portable 1TB delivers 3.3 GB/s reads and 3.0 GB/s writes — a top-tier USB4 drive for demanding professional workflows.
This drive delivers 3.3 GB/s reads and 3.0 GB/s writes — speeds that make external storage feel like internal. Move a 50GB 4K project in ~17 seconds or a 100GB asset library in ~33 seconds. No waiting, no proxies, no bottlenecks.
600 TBW endurance covers moderate daily use across a multi-year lifespan. Most externals offer 2-3 years of coverage. The 5-year warranty here is a meaningful differentiator.
Peak sequential speeds are impressive on paper, but sustained performance depends on thermal design. Without adequate cooling, expect throughput to taper during large continuous file transfers.
USB4 delivers the bandwidth needed for seamless playback and editing of high-bitrate media directly from the drive — no file transfer required.
The Corsair EX400U Portable 1TB targets users who need maximum throughput from an external drive. If you edit 4K or 6K video, move large project files between workstations, or work directly from external storage, the 3,300 MB/s read speed puts this drive in elite territory for a 1TB portable SSD.
The 1TB capacity covers most daily workflows comfortably: system backups, a working photo library, a dozen game installs, or a collection of documents and media. If you need more space, higher-capacity variants of the same product line are worth considering.
One important note: reaching the full 3,300 MB/s requires a Thunderbolt 4 or USB4 host port. On a standard USB 3.2 Gen 2 port, the drive still works perfectly but negotiates down to 10 Gbps. Most laptops from 2022 onward include a compatible port on premium models, but verify your hardware before expecting peak performance.
On paper, the Corsair EX400U Portable 1TB delivers 3,300 MB/s reads and 3,000 MB/s writes. In practice, a 50GB file — a typical 4K video project, a large game install, or a full photo shoot — transfers in ~17 seconds. A 100GB batch of raw files moves in ~33 seconds. For users who regularly shuttle large files, these transfer times are a meaningful productivity improvement over slower SATA-based externals that take 3-5x longer for the same tasks.
At 3,300 MB/s, the controller generates significant heat during extended writes. Sustained sequential transfers of 200GB or more can push controller temperatures past 70°C, triggering thermal throttling that reduces throughput by 20-35%. The aluminum enclosure helps dissipate heat, but for sustained workloads, expect speeds to settle below the rated peak after several minutes of continuous writing.
Sequential read and write speeds — the numbers manufacturers advertise — matter most when transferring single large files. For everyday tasks like opening documents, browsing photos, running applications from the drive, or loading games, random 4K performance is more relevant. All NVMe-based external SSDs deliver random IOPS in the same general range, so the $Corsair EX400U Portable 1TB feels similarly responsive to other fast portables for daily use. The real differentiator shows up during large file transfers, where the $3,300 MB/s read speed pulls noticeably ahead of slower SATA-based externals.
The $Corsair EX400U Portable 1TB is rated for $600 TBW (terabytes written) endurance. To put that in perspective: if you write 50GB per day — an aggressive daily workload for most users — the drive would take approximately $33 years to reach its endurance limit. For typical use patterns involving backups, file transfers, and game storage, the $600 TBW rating provides comfortable headroom well beyond the $5-year warranty period.
| Spec | Corsair EX400U Portable 1TB | Samsung T9 Portable SSD |
|---|---|---|
| Read Speed | 3,300 MB/s | 2,000 MB/s |
| Write Speed | 3,000 MB/s | 1,950 MB/s |
| Capacity | 1TB | 1TB |
| Interface | USB4 | USB 3.2 Gen 2x2 |
| Endurance | 600 TBW | 600 TBW |
| Score | 9.0/10 | 9.6/10 |
The Samsung T9 Portable SSD scores higher in our evaluation (9.6 vs 9.0/10). While the Corsair EX400U Portable 1TB has lower scoring, it may offer advantages in other areas like value. Review the full specifications above before deciding.
For a detailed head-to-head comparison, see our full Corsair EX400U Portable 1TB vs Samsung T9 Portable SSD comparison.
| Model | Capacity | Interface | Read | Write | TBW |
|---|---|---|---|---|---|
| Corsair EX400U Portable 1TB | 1TB | USB4 | 3,300 | 3,000 | 600 |
| Samsung T9 Portable SSD | 1TB | USB 3.2 Gen 2x2 | 2,000 | 1,950 | 600 |
| Samsung T9 Portable 4TB | 4TB | USB 3.2 Gen 2x2 | 2,000 | 2,000 | 2,400 |
| Crucial X10 Pro Portable 4TB | 4TB | USB 3.2 Gen 2x2 | 2,000 | 2,000 | 2,400 |
Specs shown for the closest High-Speed Portable SSDs alternatives. Full comparison table available on the compare page.
Corsair
Price as of Aug 3, 2026, 6:33 PM. Prices and availability are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product.