USB is the most versatile protocol when it comes to selecting an audio-interface. Both Mac and Window’s computers ship standard with multiple USB ports, and generally driver support for both Mac and Windows is well represented amongst key brands. Whilst the speeds don’t quite compare with Thunderbolt, companies like RME have proven that even USB 2.0 is more than capable of running high track counts at very low latency. Products such as the UFX II and MADIface USB can run up to 60 and 128 channels of I/O respectively.