PickGuideACASIS TBU405 Review: 40Gbps USB4 M.2 NVMe SSD Enclosure from $79.90
The ACASIS TBU405 is the product that built the brand's reputation: a 40Gbps M.2 NVMe SSD enclosure that turns a bare NVMe stick into a portable external drive running at Thunderbolt speeds. In ACASIS lab testing with a 2TB Samsung 980 Pro and an M2 MacBook Pro, it reads at around 2800MB/s — roughly five times faster than a typical 10Gbps USB enclosure. It comes in three versions: the original TBU405 (screw-fixed), the TBU405M1 (tool-free) and the TBU405Pro (tool-free with a built-in silent cooling fan), starting at $79.90.
ACASIS TBU405 series 40Gbps M.2 NVMe SSD enclosure. Interface: USB4 over USB-C, backward compatible with Thunderbolt 5/4/3 and USB 3.2/3.1/3.0/2.0 via dual-chip design. Tested speeds: ~2805MB/s read / 2734MB/s write (Samsung 980 Pro 2TB, M2 MacBook Pro). Versions: TBU405 screw-fixed ($79.90), TBU405M1 tool-free ($79.90), TBU405Pro tool-free with built-in silent fan ($84.90). Fits M.2 NVMe SSDs. Store policies: free shipping over $29 to 74 countries, 30-day trial, 2-year warranty.
Pros
- True 40Gbps USB4 performance — around 2800MB/s tested with a Samsung 980 Pro, five times faster than 10Gbps enclosures
- Dual-chip design gives unusually wide compatibility — Thunderbolt 5/4/3 and USB4/3.2/3.1/3.0/2.0 all work
- Three versions cover different needs — screw-fixed, tool-free, or tool-free with built-in silent cooling fan
- TBU405Pro's fan kept the SSD at 35°C after an hour of continuous use in ACASIS lab testing — no thermal throttling
- 2-year warranty, 30-day trial and free shipping over $29 to 74 countries — strong buyer protection for the category
- Aluminum body with fin design doubles as a passive heatsink on the fanless versions
Cons
- You need your own M.2 NVMe SSD — the enclosure ships empty, so budget for the drive separately
- SSDs with pre-installed heatsinks don't fit — ACASIS explicitly advises against them
- Real speeds depend on your port: on a plain USB 3.2 Gen2 port it falls back to 10Gbps
- At $79.90+ it costs more than basic 10Gbps enclosures — only worth it if your computer has USB4/Thunderbolt
- No on-site review count visible at the time of writing to cross-check the brand's own test claims
Who It's For
Good For
- Video editors and photographers who edit directly off an external NVMe drive and need sustained 2000MB/s+ speeds
- MacBook Pro/Air and Thunderbolt 4 PC owners who want near-internal SSD performance from a pocket-size drive
- Anyone with a spare NVMe stick from a laptop upgrade — the cheapest route to a very fast portable SSD
- Buyers who value warranty coverage — 2 years is longer than most budget enclosure brands offer
Skip If
- Your computer only has USB-A or 5-10Gbps USB-C ports — a cheaper 10Gbps enclosure gives the same real-world speed
- You want a ready-to-use drive out of the box — this is an enclosure only, no SSD included
- Your SSD has a non-removable heatsink — it won't fit the TBU405's chassis
How It Compares: ACASIS TBU405 40Gbps SSD Enclosure vs ACASIS 80Gbps Thunderbolt 5 Enclosure
| Spec | ACASIS TBU405 40Gbps SSD Enclosure | ACASIS 80Gbps Thunderbolt 5 Enclosure |
|---|---|---|
| Price | from $79.90 | Higher |
| Max speed | 40Gbps (~2800MB/s) | 80Gbps (Thunderbolt 5) |
| Chip | Dual-chip USB4 | Intel JHL9480 |
| Best with | USB4 / TB3 / TB4 computers | Thunderbolt 5 computers |
| Cooling | Aluminum fins; Pro adds fan | Active cooling |
| Best for | Most current laptops | Future-proofing, TB5 Macs/PCs |
The TBU405 is the value pick for the vast majority of current laptops, which top out at 40Gbps anyway. The 80Gbps Thunderbolt 5 enclosure only makes sense if your machine actually has a TB5 port — otherwise you pay more for speed you cannot use. Both carry ACASIS's 2-year warranty.
See ACASIS 80Gbps Thunderbolt 5 Enclosure →
Verified Ratings
Key Specs
| Interface | USB4 (USB-C), 40Gbps |
| Compatibility | Thunderbolt 5/4/3, USB4/3.2/3.1/3.0/2.0 |
| Tested speed | ~2805MB/s read / 2734MB/s write |
| SSD support | M.2 NVMe (no pre-installed heatsinks) |
| Versions | TBU405 (screw), TBU405M1 (tool-free), TBU405Pro (fan) |
| Cooling | Aluminum fin body; Pro adds built-in silent fan |
| Warranty | 2 years |
| Shipping | Free over $29, ships to 74 countries |
In The Box
- 1 × TBU405 / TBU405M1 / TBU405Pro enclosure (per version ordered)
- USB4 40Gbps USB-C to USB-C cable
- Thermal pad for the SSD
- (Screwdriver and screws included with the screw-fix TBU405)
Frequently Asked Questions
What is the difference between TBU405, TBU405M1 and TBU405Pro?
All three share the same 40Gbps USB4 interface and dual-chip design. The original TBU405 ($79.90) secures the SSD with screws. The TBU405M1 ($79.90) is the tool-free version — the SSD clips in without a screwdriver. The TBU405Pro ($84.90) adds a built-in silent cooling fan to the tool-free design; in ACASIS lab testing the internal SSD stayed at 35°C after an hour of continuous use. If you do long sustained transfers or edit video off the drive, the Pro is worth the extra $5.
How fast is it in real-world use?
ACASIS lab figures with a 2TB Samsung 980 Pro and a 2023 M2 MacBook Pro show roughly 2805MB/s read and 2734MB/s write. Real speed depends on three things: the SSD you install, your computer's port (full speed requires USB4 or Thunderbolt 3/4/5), and the file sizes being transferred. On a 10Gbps USB 3.2 port the enclosure still works but tops out around 1000MB/s.
Does it work with both Mac and Windows?
Yes. The enclosure is plug-and-play on macOS and Windows — no drivers needed. The dual-chip design (rather than a single ASMedia controller) is what gives it backward compatibility across Thunderbolt 5/4/3 and every USB generation down to 2.0, so it also works on older machines, just at the port's lower speed.
Which SSDs fit, and are there any to avoid?
It takes standard M.2 NVMe SSDs. ACASIS specifically advises against SSDs sold with pre-installed heatsinks — they are too thick for the chassis and the enclosure's aluminum body plus included thermal pad already handle heat dissipation. Popular bare drives like the Samsung 980 Pro, WD SN850X or Crucial P3 Plus are typical pairings.
What are the shipping, return and warranty policies?
ACASIS ships to 74 countries with free shipping on orders over $29 — which the TBU405 clears. Every order carries a 30-day worry-free trial and a 2-year product warranty, which is longer than the 1 year most budget enclosure brands offer. Check the shipping policy page for delivery times to your region.
Verdict
The TBU405 is ACASIS's best-seller for a reason: it delivers genuine 40Gbps USB4 performance at a price well below Thunderbolt-branded alternatives, and the dual-chip design means it works on practically any computer made in the last decade. The $84.90 TBU405Pro with the built-in silent fan is the version to get for long video transfers or editing sessions — sustained loads stay at 35°C with no throttling. Paired with a mid-range NVMe stick, it's one of the most cost-effective fast portable storage setups you can build.