Decoding USB 3.1 and USB-C

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USB3.1 is Confusing

USB 3.1 is the next generation of USB, after USB 3.0. Not too surprising, right? Well there is a bit of confusion in the what the terms USB 3.0 and USB 3.1 actually mean.

I am sure you are asking yourself how can that be, USB 3.0 has been around for years (since 2008), so why is there now confusion? This has mainly been driven by the emergence of the USB-C type connector (more on that later) and the amount of power that can now be delivered (to and from devices) over the newer standard.

USB 3.0 is dead, long live USB 3.1 Rev1

USB 3.0 and USB 3.1 Rev1 are the same thing, really they are! As we have just mentioned above USB 3.0 has been around since 2008, and along the way there have been several improvements to the original standard.

So the way to look at it is that USB 3.1 Rev1 is the “name” that developers and manufacturers (not the general public) refer to latest version of USB 3.0.

As an example one of the most noticeable changes along the way for the USB 3.1 Rev1 is power delivery. ever seen a port or USB 3.0 hub that says “Fast Charging” or “Charging” port? That is part of the “Power Delivery” standard.

USB 3.1 Rev2, SuperSpeed +

There are several important improvements with the new USB 3.1 rev2 standard:

  • Double the speed, the new standard is capable of 10Gbps. To give you perspective, this is on par with the original Thunderbolt standard
  • Much more available power, allowing the new standard to power (and charge) much larger devices. USB power delivery is now up to 100 Watts!
  • Power can be supplied by the host or the peripheral device, with previous versions of USB power could only be provide power from the host side only

The speed improvements will mean that more devices can be used effectively at once on a single port. Our original article on the differences between USB 2.0 and USB 3.0 pointed out that external hard drives may actually be slower that the USB 3.0 transfer rate.

As you can imagine with the SuperSpeed+ revision, that is going to still apply. However if you have a external drive that has an internal SSD instead of a mechanical drive, then you will more than likely be able to use the higher transfer speed.

Power is another major consideration with the newer standard, not only is there more power available than with USB 3.1 Rev1, power can now be supplied in BOTH directions. This is how a laptop can have just one single port to drive and power peripherals as well as be charged through that port as well.

USB-C, the same as USB 3.1 Rev2, or not?

USB-C is not a type or revision of USB, it is a connector type, it can also be used to support DisplayPort, MHL and Thunderbolt 3.

This is something that everyone has been waiting for, but they may not know it just yet. The USB-C connector introduces some interesting and very convenient features:

  • It is small, about the same size as a USB 2.0 Micro connector
  • Here’s the big one - It can be inserted either way up! No more fumbling around with connectors that have to be inserted one way only
  • It can support USB3.1 data, USB power delivery AND DisplayPort A/V over one connector (and cable).

As the new USB standard and connector type becomes more widely adopted then you will find that the only cable you will need will be a USB-C to USB-C cable.

This is good news for everyone as the end user will not have to carry around a bunch of different cables and manufacturers and distributors will not have to manufacture as many different cables!

Considerations for USB-C cables

Even though the new USB standard and connector type are going to make life easier for everyone, there is something new to consider…

In the brand new, brave world of USB-C, USB 3.1 Rev2 and higher power delivery, all cables will not be the same! They will have the same connectors, but may not have the same capabilities.

Here are the important points to note:

  • Some cables may not support USB Power Delivery (no charging for you)
  • Some cables may only support up to 65W of USB Power Delivery
  • If you want 100W of USB Power Delivery that is going to means a thicker, bulkier cable
  • A cable that is marked USB 3.1 will support both revisions (generations) of the standard

The point here is that you need to look at the specifications of the cable you are buying more closely than you have before. Don’t rush out and just buy a USB-C cable, look at the specifications for that cable and make sure it actually does what you need it to do!

It’s not just about the cable

During your USB 3.1/USB-C adventure you have to make sure of one other thing. The device(s) you are connecting with you cable have to also be capable of what you are expecting.

If the device that you are connecting does not support USB Power Delivery, guess what! It doesn’t matter if you have the biggest bad ass cable in the world, that device is not going to be powered or charge.

Here is an example; if you have an expensive 4K flat panel TV, connect that to a $99 DVD player expecting to get 4K on the screen, disappointment is in your future. Don’t blame the HDMI cable you used to connect the two, the issue is with the DVD player. Same holds true here for the new USB standard.

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