Chapter 2: Key Information About USB-C

USB-C is a standard for cables, connectors, and sockets established by the Universal Serial Bus Implementers Forum (USB-IF). It is designed to replace a variety of older cables, including miniUSB, micro-USB, USB A, and B, along with power, video, and audio cables.

Unlike previous standards, USB-C features a single connector type that can be plugged in either way and is notably slim and compact.

This design is incredibly convenient. How many times have you fumbled around trying to figure out how to insert a cable? While turning the device around is an option, it often means clearing off a cluttered desk first.

The simplicity of having just one connector is beneficial, but the functionality depends on various cables and protocols, as we'll explore.

From a user perspective, USB-C, combined with specific data protocols, can charge devices and facilitate data transfer between them (for storage, video, audio, etc.).

Don't be intimidated by the term "protocol." It simply refers to an agreed-upon method for data exchange.

While separating data transfer from power delivery enhances flexibility, it also introduces complexity. Ensuring that both devices at either end of the USB-C cable utilize the same protocol is crucial.

Section 2.1: Compatibility with USB 2.0 Devices

Let’s clarify this right away: USB-C does work with USB 2.0 using an adapter. However, in certain situations, the orientation of the cable can be critical, which is contrary to the design principle of USB-C.

For example, I have a USB-C extender cable that only functions if inserted in a specific way.

This situation is rare, but it’s worth being aware of when using older technology.

Section 2.2: Charging Capabilities of USB-C

Let’s tackle the straightforward aspect first: power delivery.

USB-C cables and ports can operate without a data protocol, which is helpful if your primary need is charging devices.

Historically, USB could only provide a limited amount of power—500mW was typically the maximum. However, as mobile device usage grew, charging capabilities became a priority.

Basic USB-C allows for 15-watt charging, adequate for most smartphones.

Moreover, USB-C supports bidirectional charging. For instance, a tablet might draw power from a charger while simultaneously charging a smartphone through the same port, provided the devices are compatible.

Quick recharging is also possible, with USB-C Power Delivery (PD) enhancing charging capabilities up to 100 watts. This feature is especially beneficial for larger devices like laptops.

However, USB-C PD is not included in the basic USB-C specification, so it’s essential to verify that your device supports it, along with having a power supply capable of delivering 100 watts.

Section 2.3: Understanding Data Protocols

The naming conventions for data protocols can be confusing, often resembling the cable specifications.

Data travels through the cable using one or more lanes, which can be combined for faster data transfer.

Here’s a breakdown of the most relevant information:

• USB 3.2 Gen 1: Allows data transfer at 5Gbps over a single lane. Previously known as USB 3.1 Gen 1, it's now marketed as SuperSpeed USB 5Gbps.
• USB 3.2 Gen 1x2: Utilizes two 5Gbps lanes for a total of 10Gbps, referred to as SuperSpeed USB 10Gbps.
• USB 3.2 Gen 2x1: Operates on a single lane with 10Gbps, often called SuperSpeed USB 10Gbps.
• USB 3.2 Gen 2x2: Combines two lanes of 10Gbps for a total of 20Gbps, now marketed as SuperSpeed USB 20Gbps.

Why are these names important? Because they can often be used interchangeably in advertising, and it’s crucial to know what you’re purchasing, especially for high-end equipment.

All data protocols are backward compatible, meaning you can use older flash drives with modern laptops, albeit at reduced speeds.

To complicate matters further, USB-C can also handle Intel’s Thunderbolt 3 and 4 data transfer technologies, theoretically achieving speeds up to 40Gbps and allowing for the connection of multiple devices.

Section 2.4: USB-C for Video Connections

USB-C supports various monitor protocols via alternate mode (Alt Mode), which specifies the type of video encoding that the monitor requires.

You can connect monitors with HDMI, DisplayPort, or VGA interfaces using a simple adapter. If supported by the protocol and computer, you can daisy-chain multiple monitors through a single port.

When using multiple monitors on a single port, you’ll need a protocol that can handle the necessary bandwidth—this is where Thunderbolt technology becomes essential.

Section 2.5: Thunderbolt and USB-C Explained

Intel oversees the Thunderbolt standard, which is positioned similarly to how USB-IF presents USB-C. Thunderbolt can utilize USB-C cables and connectors for its functionality.

Thunderbolt 4 ports are versatile and compatible with a range of connection standards, including previous Thunderbolt versions, USB, DisplayPort, and PCIe. They also accommodate standard USB-C connectors.

In the context of USB-IF, USB-C can leverage Thunderbolt as a data protocol, while from Intel’s perspective, Thunderbolt operates using USB-C and other technologies.

This duality may seem confusing, but it’s essential to note that Thunderbolt is frequently referenced in discussions about monitors, though it also facilitates data transfer across devices, including storage solutions.

Both Thunderbolt 3 and 4 offer speeds up to 40Gbps and can support multiple 4K displays or a single 5K display, contingent on the host computer’s capabilities.

Section 2.6: Using USB-C with Hubs or Docks

Many laptops and tablets come equipped with a limited number of USB-C ports, sometimes just one. Fortunately, the protocols that operate via USB-C allow for device chaining.

You can enhance connectivity by investing in a hub or dock that expands a single USB-C port into several USB-A ports, HDMI ports, an SD card slot, and possibly an additional USB-C port.

Since USB-C can transfer data and charge devices simultaneously, a dock or hub can also provide power to your device.

From experience, I recommend selecting a hub or dock that includes an extra USB-C port. This will enable you to charge a tablet while utilizing HDMI ports and other connections.

However, avoid opting for the cheapest options; I’ve had hubs that overheated and ultimately failed after choosing a low-cost alternative.

Case Study: Connecting Monitors to Mac

The ability to connect peripherals to a computer or tablet hinges on a few factors:

• The host computer’s processing power and available ports
• Any adapters or hubs being used
• The specifications of the peripheral

Even if a cable can support speeds of 40Gbps, the host must be capable of processing data at that speed.

Here are a few scenarios:

• Mac computers with the Apple M1 Chip: Can only connect one monitor via USB-C, even with a dock. (A Mac mini can support an additional monitor via a separate HDMI port.)
• Macs with multiple USB-C and Thunderbolt 3 ports: Can connect one monitor to each port.
• Macs with Thunderbolt 4 ports (USB-C) and HDMI ports: Can support up to four monitors.

Interestingly, a Mac Studio with the M1 Ultra can handle up to five external displays—four Pro XDRs (6K at 60Hz) via USB-C and one 4K display through HDMI.

It’s crucial to note that each monitor requires its own port; chaining monitors is not an option. Simply having a fast Thunderbolt 3 or 4 port does not guarantee multiple monitor support, so always consult the manufacturer’s specifications.

Case Study: 2021 iPad Pro 12.9”

The 2021 iPad Pro 12.9” features a single USB-C port that supports:

• Thunderbolt 3
• Native DisplayPort over USB-C
• VGA, HDMI, DVI, and Thunderbolt 2 through adapters

While Thunderbolt 3 can manage the bandwidth for two 4K displays, the iPad Pro itself only supports one monitor. This limitation may be linked to the M1 chip.

Overview of USB4

USB4 is not a new cable or connector standard but rather a new data protocol.

What are the benefits? Like Thunderbolt 3 and 4, USB4 can handle data at speeds of 40Gbps and offers improved configurability.

The USB-IF announced the specification in 2019, but as of January 2022, devices utilizing USB4 were still in development.

Final Thoughts

Recently, I heard Alex Lindsay mention on MacBreak Weekly that USB Type-C was a chaotic standard, and initially, I disagreed. I considered USB-C a significant advancement over USB 2.0 with its multiple plug types.

However, after Apple announced that M1 iPads would support external monitors via USB-C, I decided to investigate further, unknowingly entering a complicated landscape filled with acronyms that often refer to the same concepts.

In retrospect, Alex was correct; USB-C can indeed feel like a tangled mess.

Have you encountered any frustrating experiences with USB-C technology?