The USB Promoter Group has just announced the USB 3.2 spec update with one major change over USB 3.1: multi-lane operation on hosts and devices and thus double the bandwidth on existing SuperSpeed Type-C cables.

With USB 3.1, both hosts and devices were designed for single-lane use. The SuperSpeed cables, however, were designed with multi-lane in mind, but weren't able to make use of it because the devices they connected to on both ends didn't support it. Thanks to USB 3.2, upcoming certified hosts and devices will support multi-lane operation so existing cables can benefit from double the speed when connected to them.

As Google's Benson Leung more accurately explains, the existing Full-Featured USB-C cables have 15 wires with 8 being SuperSpeed ones. Currently, 4 out of these 8 are used for USB-only operations while the other 4 lay dormant until they're called upon for alternate modes like DisplayPort. By connecting these cables to 3.2 hosts and devices, they'll instead use all 8 wires, essentially doubling their bandwidth. Gen 1 "SuperSpeed USB" cables will go from transmission speeds of 5Gbps to 10Gbps, while Gen 2 "SuperSpeed USB 10 Gbps" will double to 20Gbps. Sure, that won't confuse anyone...

Cables with the certification on the left will go up to 10Gbps, those with the right one will go to 20Gbps.

The USB 3.2 spec is in final draft review phase and will be published around September so developers can use its guidelines for their products.

Via: +Benson Leung

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