Lately, a new port has become one of the seemingly ‘universal’ ports – the USB Type-C (or simply USB-C) port. Is this real innovation that helps simplify lives, or is it all about the jumbled fuss of more cables and adapters? Let’s find out.
First of all, some clarification
The USB specification is fragmented and confusing, so first, we’ll need to clarify a common misunderstanding.
There is one thing you need to keep in mind: there are two different specifications that this article will explain simultaneously – the USB protocol specification and the USB port specification.
USB Protocol Specification specifies the available bandwidth, power limits and capabilities of the USB connection. These are numeric, like USB 1.0, USB 2.0, USB 3.0 etc.
USB Port Specification refers to the size and shape of the physical USB ports, and the pins in these ports. There are alphabetic, like USB Type-A, USB Type-B, USB Type-C (or simply UBS-A, USB-B and USB-C). Some of these ports also have a mini or micro version, like Micro-USB A, Mini-USB B etc.
This article will go through the details of these specifications later. For now, just remember that numbered specification/version (like USB 2.0) refer to the USB Protocol, while alphabetic specifications (like USB-C) refer to the physical port used for the connection.
A Brief History of USB
Development on the Universal Serial Bus (USB) started in 1994-1995 by several companies including IBM, Intel, Microsoft and Compaq, with Ajay Bhatt being a major contributor in the development. The goal was to have a simple & universal connector to connect peripheral devices.
Further development on USB and newer specifications has been summarized in the following table.
|This icon refers to a USB Port Specification
||This icon refers to a USB Protocol Specification
||Two speed modes:
- Low Speed mode – upto 1.5 Megabits per second (Mbps)
- Full Speed mode – upto 12 Mbps
Upto 2.5W power transfer at 5V (500mA max)
USB 1.0 certification logo
||First connector under the USB standard, supported USB 1.0, USB 1.1 and USB 2.0. It has 4 pins – 2 for power and 2 for data.
||Fixed some problems with USB 1.0, mainly with USB Hubs.
Widely adopted by manufacturers.
(aka High-Speed USB)
|First major revision of the USB Protocol.
Transfer rate of upto 480 Mbps, same power delivery specifications as USB 1.0.
USB 2.0 certification logo
||Not very popular, rarely seen on devices.
Mini-USB A Connector
||Square port connector, still commonly used in printers and scanners. Supports USB 1.0, USB 1.1 and USB 2.0 connections.
||It was commonly seen in feature phones. Rarely used now.
Mini-USB B connector
(popularly called Micro-USB)
|Very popular, especially in portable devices such as phones and tablets. Claimed a life of upto 10,000 insertion-removal cycles.
Micro-USB B connector
(aka SuperSpeed USB)
(Later unnecessarily renamed to USB 3.1 Gen 1)
|Transfer speeds of upto 5 Gigabits per second (Gbps).
New Power Delivery standards, allowing upto 7.5W at 5V (1.5A max)
USB 3.0 certification logo
|Revised SuperSpeed connectors
||To achieve higher bandwidth, USB 3.0 requires 5 more pins than USB 2.0-compatible ports have. Thus, new port connectors were introduced with 5 more pins. The best thing is that all these port connectors are backwards compatible with their respective USB 2.0 versions.
SuperSpeed USB-A connector (Many manufacturers made SuperSpeed USB-A ports blue to differentiate them from slower USB-A ports)
Note: SuperSpeed USB-A connector also supported USB 3.1 Gen 2 released later
SuperSpeed USB-B connector
SuperSpeed Micro-USB B connector
||USB 3.1 Gen 2
||Greater transfer speeds of upto 10 Gbps
Newer power delivery standards, allowing upto 60W at 12V (max 5A) or 100W at 20V (max 5A). This is a leapfrog improvement over previous power delivery standards, and it allows ultrabooks and laptops to be charged via USB.
Works on USB-A and USB-C connectors.
USB 3.1 Gen 2 certification logo
||USB Type-C aimed to be the One Port to Rule Them All
First ever reversible USB connector.
Miniature form factor, allowing thinner ultrabooks and other mobile devices.
Compatible with USB 3.1 Gen 2 and all previous USB Protocol Standards.
Since USB-C supports USB 3.1 Gen 2, it supports power delivery upto 100W. This enables modern ultrabooks and laptops to be charged via a USB-C port. (Like Apple’s new MacBook has a single USB-C port for charging and data transfer).
What the fuss is all about – Thunderbolt
From the table above, USB-C seems pretty straightforward – it supports upto 10 Gbps transfer speed and upto 100W power delivery because it runs on USB 3.1 Gen 2. But since don’t we live in a non-ideal world, things don’t end here.
In 2011, Apple and Intel introduced a new interface to connect peripherals and displays – Thunderbolt. Thunderbolt is very different from (and also faster than) USB because runs on the PCIe interface. PCIe is the ‘backbone’ interface on the motherboard, onto which essential devices such as Graphics Cards and Sound Cards are connected. Thunderbolt has had two revisions since the initial release – conveniently named Thunderbolt 2 and Thunderbolt 3. Thunderbolt 1 & Thunderbolt 2 utilized the Mini DisplayPort connector.
Thunderbolt 1/2 connector (same as a Mini DisplayPort connector)
Now comes the fussy part – Thunderbolt 3. Thunderbolt 3 supports bi-directional transfers upto 40 Gbps. Instead of using the Mini DisplayPort Connector, Thunderbolt 3 utilizes the USB-C connector.
Thunderbolt 3 connector (same as USB-C connector)
USB-C ended up being a modern, compact and reversible connector used for two completely different interfaces – USB 3.1 and Thunderbolt 3, which has led to some confusion among customers. Thankfully, since Thunderbolt 3 is superior to USB 3.1, most (if not all) Thunderbolt 3 USB-C ports also support USB 3.1 Gen 2.
Left – A USB 3.1 Gen 2 port on a desktop
Right – A Thunderbolt 3 port on an ultrabook
Visually, the two can’t be told apart because both interfaces use the same physical connector
A Potential Threat to Gaming Laptops
Graphics Processing Units (GPUs) or Graphics Cards are pieces of hardware that make your machine capable of rendering models/simulations and running high-end games. Conventionally, there were dedicated Gaming Laptops with powerful GPUs. One major drawback of gaming laptops is that they are thick and bulky and heavy because of the powerful internals, bigger batteries to power high-end GPUs and better cooling systems.
In 2014, gaming laptops and desktops manufacturer Alienware demoed its Alienware Graphics Amplifier, the first-ever commercially available way to attach graphics cards externally. This opened a possibility for portable laptops that can be connected or docked to External Graphics Cards. The Alienware Graphics Amplifier uses a proprietary connector to connect a desktop Graphic Card to a laptop (over the previously mentioned PCIe interface).
The Alienware Graphics Amplifier with a high-end desktop GPU connected to an Alienware laptop using a proprietary connector
Since Graphics Cards need to run on the PCIe interface, Thunderbolt 3 (which also supports PCIe)and USB-C have made standardized External GPU solutions a reality. The Razer Core is a standard External GPU solution that can be used to attach a desktop GPU to any laptop with Thunderbolt 3 over USB-C (This won’t work over a USB-C port with just USB 3.1).
The Razer Core connected to an ultrabook over Thunderbolt 3 and USB-C
External GPUs pose a threat to future gaming laptops, since they enable portable ultrabooks to be even more powerful than conventional gaming laptops by just plugging in a USB-C cable. With this, a single machine can be the best of both worlds – an ultraportable device when mobile, and a powerful gaming beast when docked.
Although the USB standards have been regularly updated, this time is different. We now have a small, reversible connector that enables completely new interfaces and connections – from faster storage devices to monitors with more resolution, and from laptop chargers to external graphics cards – all over a single mighty port, USB-C. This versatility also ensured that the breakthrough USB-C is a confusing addition to the already-confusing family of USB ports and protocols.