5Gbps is conveniently unambiguous, but 10 and 20 exist in variations that use four lanes and in variations that use two lanes. According to Wikipedia, the symbo

5Gbps is conveniently unambiguous, but 10 and 20 exist in variations that use four lanes and in variations that use two lanes. According to Wikipedia, the symbols with a number are only specified for the four lanes version, but there's little doubt that half-width cables will also be be advertised with whatever bandwidth latest devices could funnel through.