Thunderbolt 3 real speed: 21.6Gbps

[Mr Dobey]

In talks with both Sonnet Tech and Akitio, they have both independently told me that the real world speed of Thunderbolt 3 tops out at 21.6Gbps (2.7GBps) instead of the market 40Gbps. Even with a minor 3% hit from the 128b/130b encoding overhead of PCIe 3.0, these claims are about half of what is advertised. For whatever reason neither company will give a technical breakdown of why this is so.

Has anyone here made a very fast setup such as RAID 0 of NVMe drives that could test this bandwidth claim over Thunderbolt 3?

 

[DRDR]

I am using a Thunderbolt 3 to Dual Displayport Adapter, driving two 4K displays. According to the Displayport standard this means the following data rate from one of my Thunderbolt 3 ports to the displays:

2 x 12,96 GBit/s = 25,92 GBit/s

This is the exact same data rate used when connecting a 5K display.

 

[MrX8503]

That's not possible because the LG 5K is using the full 40Gbps.

5K + 3x USB ports + webcam + speakers = ~40Gbps

 

[dyn]

Did they also tell you how they tested it and what they used for the test? Without knowing that it's just throwing out numbers which says absolutely nothing at all.