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EX300U USB 3.2 External SSD: Everything You Need to Know

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The CORSAIR EX300U is a palm‑size, USB‑C external SSD built for quick transfers, on‑the‑go edits, and everyday backups. It delivers up to 1,100 MB/s reads and writes over USB 3.2 Gen 2 (10 Gbps), and even snaps to your phone or other metal surfaces with a MagSafe‑compatible magnetic ring.

What is EX300U?

Think of EX300U as fast, pocketable solid‑state storage. Plug it into a USB‑C port and you can move big projects, record footage to a phone, without the noise or fragility of a hard drive. It supports Windows, macOS, iOS/iPadOS, and Android out of the box. (iOS/iPadOS 13 or later.)

EX300U Portable SSD_Render_09

EX300U Specs

Specification 1000GB (1TB) 2000GB (2TB) 4000GB (4TB)
Interface USB 3.2 10Gb USB 3.2 10Gb USB 3.2 10Gb
Controller Phison PS2217-17 Phison PS2217-17 Phison PS2217-17
NAND 3D NAND 3D NAND 3D NAND
DRAM Cache No DRAM cache No DRAM cache No DRAM cache
NAND Cache Dynamic pSLC Dynamic pSLC Dynamic pSLC
Encryption Not supported Not supported Not supported
TRIM Support Supported Supported Supported
S.M.A.R.T Support Supported Supported Supported
Garbage Collection Supported Supported Supported
TBW Rating 250 TBW 500 TBW 1000 TBW
MTBF 1,400,000 hrs 1,400,000 hrs 1,400,000 hrs
Idle Power <12.5 mW <12.5 mW <12.5 mW
Avg Active Read 3.0 W 3.2 W 3.5 W
Avg Active Write 3.0 W 3.2 W 3.5 W
Operating Temp 0°C ~ 70°C 0°C ~ 70°C 0°C ~ 70°C
Storage Temp -40°C ~ 85°C -40°C ~ 85°C -40°C ~ 85°C
Operating Humidity 90% RH (40°C) 90% RH (40°C) 90% RH (40°C)
Storage Humidity 93% RH (40°C) 93% RH (40°C) 93% RH (40°C)
Shock 500 G 500 G 500 G
Vibration 20Hz–80Hz/1.52mm, 80Hz–2000Hz/20Gp-p 20Hz–80Hz/1.52mm, 80Hz–2000Hz/20Gp-p 20Hz–80Hz/1.52mm, 80Hz–2000Hz/20Gp-p
Dimensions (mm/in) 64.3 × 64 × 12 mm / 2.53" × 2.52" × 0.47" 64.3 × 64 × 12 mm / 2.53" × 2.52" × 0.47" 64.3 × 64 × 12 mm / 2.53" × 2.52" × 0.47"
Sequential Read (CDM) Up to 1,100 MB/s Up to 1,100 MB/s Up to 1,100 MB/s
Sequential Write (CDM) Up to 1,100 MB/s Up to 1,100 MB/s Up to 1,100 MB/s

EX300U Transfer Speeds

  • Rated speed: Up to 1,100 MB/s sequential reads and writes when connected to a USB 3.2 Gen 2 (10 Gbps) port. That’s quick enough to copy a 20 GB 4K clip in roughly 20 seconds in ideal conditions.

Tip for Windows: enable Disk Write Caching for best results! Device Manager → Disk drives → your EX300U → Policies tab → enable caching.

What makes it different?

  • MagSafe‑compatible magnetic ring: attaches to iPhones or other metal surfaces for hands‑free, mobile capture and editing.
  • Multi‑device friendly: Works with PC, Mac, consoles, iOS/iPadOS, and Android via USB‑C.
  • Compact & travel‑ready: A square, low‑profile chassis at 64.3 × 64 × 12 mm slips into any pocket.
corsair ex300u

Will it work with my device?

  • Connection: USB‑C recommended. The EX300U is not recommended for hosts with only USB‑A.
  • Operating systems: Plug‑and‑play with Windows, macOS, iOS/iPadOS (13+), and Android.

Is it good for creators and gamers?

Yes if you’re moving footage, backing up photo libraries, shuttling project files, or carrying games between systems, EX300U’s 10 Gbps USB link and 1,100 MB/s class performance hit the mainstream sweet spot. For higher‑end workflows (heavier 4K/8K or raw capture), CORSAIR’s EX400U family moves to 40 Gbps USB4/Thunderbolt with up to 4,000/3,600 MB/s speeds.

How do I get the best performance?

  • Use a USB‑C port labeled 10 Gbps (USB 3.2 Gen 2) or better. Slower ports cap speeds.
  • Enable Windows write caching before benchmarking.
  • Keep an eye on available space. Like many DRAM‑less SSDs with pSLC caching, sustained write speeds can drop if the cache is exhausted; leaving headroom helps.

What does “USB 3.2 Gen 2” mean?


It’s a 10 Gbps USB‑C connection. In practical terms, that’s enough bandwidth for ~1,100 MB/s transfers with the right host port and cable.



Does it support hardware encryption?


No hardware encryption isn’t supported. If you need encryption, use OS‑level software encryption.



Will it stick to my iPhone?


Yes the chassis includes a MagSafe‑compatible magnetic ring for easy attachment



Is it console‑friendly?


The Product Overview positions EX300U for PC, Mac, consoles, and mobile over USB‑C. Console behavior varies by platform and title, but mass‑storage use is supported.



What are the endurance ratings?


Estimated TBW is 250 TBW (1TB), 500 TBW (2TB), 1000 TBW (4TB), with 1.4M‑hour MTBF.



Is there software?


Yes EX300U works with CORSAIR SSD Toolbox and carries a 3‑year warranty.



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