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QNAP CAB-TBT315M-40G Thunderbolt 3 Cable 1.5 m
A 40Gbps active Thunderbolt 3 link for QNAP Thunderbolt NAS and direct-attached storage.
Thunderbolt 3 40GbpsActive 1.5 mBi-directionalUSB-C connectors
The QNAP CAB-TBT315M-40G is a 1.5-metre active Thunderbolt 3 cable with USB-C connectors on both ends, rated for bi-directional transfers up to 40Gbps, intended to connect a Mac or PC with Thunderbolt to QNAP Thunderbolt NAS and storage such as the TVS-h874T or TBS-h574TX. Active signal conditioning keeps the full Thunderbolt 3 rate at 1.5 m, longer than a typical passive 40Gbps cable.
It suits video editors and creative studios that use Thunderbolt-to-NAS direct connections for large media files, where a certified 40Gbps link avoids dropping to 20Gbps or USB speeds.
Compatibility Note: QNAP does not publish a detailed specification sheet for this cable; the data here comes from the distributor listing and reseller information. Use it between Thunderbolt 3/4 ports — as a first-generation active Thunderbolt 3 cable it is not intended for USB-only devices, USB-C video (DP Alt Mode) monitors or high-wattage charging.
Key Features
Full 40Gbps Thunderbolt 3
Active design keeps 40Gbps Thunderbolt 3 bandwidth across 1.5 m, for Thunderbolt NAS, RAID enclosures and 10GbE Thunderbolt adapters.
Made for QNAP Thunderbolt NAS
Matches QNAP Thunderbolt models, letting a workstation attach directly to the NAS for fast editing and backups without a network switch.
Longer than passive 40G cables
At 1.5 m it reaches from a desk to a NAS on the floor or a shelf where 0.5–0.8 m passive cables fall short.
Technical Specifications
| Identification |
| Part Number |
CAB-TBT315M-40G |
| EAN / GTIN |
4711103083994 |
| MPN |
CAB-TBT315M-40G |
| Brand |
QNAP |
| Connectivity |
| Connectors |
USB-C male to USB-C male |
| Length |
1.5 m |
| Cable type |
Active Thunderbolt 3 cable — per distributor data |
| Performance |
| Interface |
Thunderbolt 3 |
| Data rate |
Up to 40Gbps, bi-directional |
| USB / DP Alt Mode use |
Not specified by QNAP — intended for Thunderbolt-to-Thunderbolt connections |
| Power Delivery |
Not specified by QNAP |
| Physical & support |
| Colour |
Black |
| Warranty |
1 year (per reseller data) |
Frequently Asked Questions
Does the QNAP CAB-TBT315M-40G work with Thunderbolt 4 and 5 Macs?
Thunderbolt 4 and 5 ports are backward compatible with Thunderbolt 3 devices and cables, so the connection runs at Thunderbolt 3 speed (40Gbps) when both ends are Thunderbolt.
Can I use it to connect a USB-C monitor or charge a laptop?
It is not designed for that. Active Thunderbolt 3 cables of this generation are optimised for Thunderbolt data; for USB-C video and charging use a USB-C or Thunderbolt 4 cable such as the Apple MW5J3ZM/A.
Which QNAP devices is it meant for?
QNAP Thunderbolt NAS and storage expansion units, for example the TVS-h874T, TVS-h674T, TS-h966TX and TBS-h574TX, connected directly to a Thunderbolt workstation.
Singular Expert Insight
We recommend the CAB-TBT315M-40G when you link a Thunderbolt workstation directly to a QNAP Thunderbolt NAS and need a little more reach than a passive cable. For mixed use — displays, charging and USB devices as well as Thunderbolt — the Apple Thunderbolt 4 Pro Cable MW5J3ZM/A (1.8 m, 40Gb/s, 100W) is more versatile.
✓ Buy it if you connect a Mac or PC to a QNAP Thunderbolt NAS or DAS and want 40Gbps at 1.5 m.
✕ Skip it if you need USB-C video, laptop charging or plain USB device support from the same cable.
→ Also consider Apple Thunderbolt 4 Pro Cable MW5J3ZM/A (1.8 m, 40Gb/s, 100W, DisplayPort).