- Connecting
- Need
- Answer
Cable for a 20 Gbps SSD
Get this
USB-C cable marked 20Gbps or 40Gbps, 1 m or shorter; the host port must support USB 3.2 Gen 2x2
Look for
- Host: "USB 3.2 Gen 2x2" or "USB 20Gbps" port (most Macs and many laptops lack it)
Avoid
- Expecting 2,000 MB/s on a Mac: Gen 2x2 SSDs run at 10 Gbps there
Speed in practice
| Link | Signalling | Typical real copy speed |
|---|---|---|
| USB 2.0 | 0.48 Gbps | 35–40 MB/s |
| USB 5Gbps | 5 Gbps | 400–450 MB/s |
| USB 10Gbps | 10 Gbps | 900–1,050 MB/s |
| USB 20Gbps | 20 Gbps | 1,800–2,000 MB/s |
| USB4 / Thunderbolt 40Gbps | 40 Gbps | 2,800–3,800 MB/s |
Typical figures for good drives, as commonly measured; slower drives won't reach them.
Standards behind this answer
2017
USB 3.2 Gen 2x2 (20 Gbps)
Two 10 Gbps lanes at once over USB-C. Fast, but host support is patchy.
- data: 20 Gbps
- video: No (only via USB-C Alt Mode)
- power: 4.5 W (port)
USB4 (20 and 40 Gbps)
Thunderbolt 3's protocol, opened up as a USB standard. Tunnels USB, DisplayPort and PCIe over one cable.
- data: 20 or 40 Gbps
- video: DisplayPort tunnelled
- power: USB PD required