Why don't iConnectivity interfaces have USB 3?

A question we frequently get asked is why we use USB 2 for our audio interfaces instead of USB 3, because "USB 3 is much faster".

This is based on a misunderstanding of what USB speed really means. In fact, data moves at exactly the same speed over USB 3 as it does over USB 2 - it's just that USB 3 has more bandwidth, which simply means it carries more data in the same amount of time.

Let's take an example: imagine you have a truck full of cargo driving at top speed down a single lane highway. That's USB 2. Now imagine you build that out to be a six lane highway. That's USB 3. Now you can have 6 trucks driving down the highway at the same time - but all of the trucks are still going at the same speed. You can carry more cargo in one journey, but the journey will still take the same amount of time for each truck. So if all you need to transport is one truckload of cargo it makes no difference at all whether you are driving on a single lane highway or a 6 lane highway - your cargo will still arrive at the same time.

So that's the real difference: USB 3 is made for carrying larger loads. It's not made to carry the same load quicker.

USB 2 Hi-Speed has a bandwidth of 480 Mbits/second. This is more than enough bandwidth to carry multiple channels of hi-resolution digital audio, and literally thousands of channels of MIDI data (i.e. it's only one truckload of cargo). Whether you are using USB 2 or USB 3 that data is sent at the speed of electrical signals - which is 280,000,000 meters per second. That should be a fast enough truck for anyone! :-)

Note that there is also a disadvantage to using USB 3. Because of the higher bandwidth of USB 3 it has a lower maximum cable length. Whereas USB 2 cables have a max length of 5 metres (about 16 feet), USB 3 cables can't be longer than 3 metres (about 10 feet). Any longer than that and your signal may have dropouts.

So by using USB 2 your audio & MIDI is not only going to travel to its destination at exactly the same speed as USB 3, it's actually more reliable over longer cables as well.