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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 1TB USB4 portable — 3300 MB/s read on a Thunderbolt 4 / USB4 host. The EX400U is the rare USB4 drive that supports the full 40Gbps link (not all USB4 drives do). 5-year warranty is best-in-class for the speed tier.
See how it stacks up against competitors in our USB-C External SSDs SSD comparison, or browse related SSD buying guides.
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Professional-grade USB4 storage with 3.3 GB/s reads and 3.0 GB/s writes — the Corsair Corsair EX400U 1TB keeps your creative workflow moving.
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.
Rated at 600 TBW, this drive handles a solid mix of daily reads and writes. A 5-year warranty backs this drive, signaling manufacturer confidence in its longevity.
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 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 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 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 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 1TB | Samsung T9 2TB |
|---|---|---|
| Read Speed | 3,300 MB/s | 2,000 MB/s |
| Write Speed | 3,000 MB/s | 2,000 MB/s |
| Capacity | 1TB | 2TB |
| Interface | USB4 | USB 3.2 Gen 2x2 |
| Endurance | 600 TBW | 1,200 TBW |
| Score | 9.0/10 | 9.6/10 |
The Samsung T9 2TB scores higher in our evaluation (9.6 vs 9.0/10). While the Corsair EX400U 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 1TB vs Samsung T9 2TB comparison.
| Model | Capacity | Interface | Read | Write | TBW |
|---|---|---|---|---|---|
| Corsair EX400U 1TB | 1TB | USB4 | 3,300 | 3,000 | 600 |
| Samsung T9 2TB | 2TB | USB 3.2 Gen 2x2 | 2,000 | 2,000 | 1,200 |
| Samsung T9 Portable SSD | 1TB | USB 3.2 Gen 2x2 | 2,000 | 1,950 | 600 |
| Crucial X10 Pro 2TB | 2TB | USB 3.2 Gen 2x2 | 2,000 | 2,000 | 1,200 |
Specs shown for the closest USB-C External SSDs alternatives. Full comparison table available on the compare page.
The Corsair EX400U comes in multiple capacities. Smaller sizes save money if you do not need the headroom; larger sizes drop the cost-per-TB for media libraries and Time Machine backups.
Corsair
Price as of Jul 3, 2026, 4:46 AM. 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.
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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.
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Price as of Jul 3, 2026, 4:11 AM. 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.