Everything You Need to Know About USB Cables

With the launch of the iPhone 15 and Apple’s move to a USB-C port, there may be a lot of confusion about finding the right power cable for your device. Read on to discover more about the different flavors of USB and some advice on finding the right cable for your phone.

What is USB?

USB is short for Universal Serial Bus.  First introduced in 1996 by several American companies, including IBM, Intel & Microsoft, the technology was launched with the goal of creating a simpler way of connecting hardware to personal computers.  Prior to the USB launch, computers needed different ports to connect different peripherals like monitors and keyboards.  With the introduction of USB all of these devices could connect via one, standard port. 

Physically, USB ports have evolved over time, from the teen-tiny Micro to the rectangular USB-A and, ultimately, the super-sleek, and most recent, USB-C.  As the ports have change physically so too have the capabilities of the technology, including their ability to handle power and data transfer speeds.

What are the Different Versions of USB?

A lot of the confusion with USB can be attributed to the fact that there are multiple versions of USB.  And, within USB-land, there are both version names and marketing names.  While the physical port remains the same, the different versions have separate data transfer capabilities.  While there are additional versions (ie. 3.0, 3.1, etc.), the three main versions of USB data transfer to know are USB 2.0, USB 3.2 and USB 4, with the differences summarized in the table below.


Old Spec

Marketing Name

Data Transfer Speed

Photo Copies per 1 min

HD Movie Copies per 1 min



Hi Speed





3.0 or 3.1


Up to 20Gbps





USB 4®

Up to  80Gbps



So, as you can see, the main differentiators as you move through the different versions comes in the form of data transfer speeds.  In short, as you move from USB 2.0 to 4, your data transfer speed increases 166 times over, meaning the time required to transfer goes down significantly. 

Although the data transfer speeds will differ, there is one area in which the cables, for all intensive purposes, are relatively the same.

Charging Speed

The speed at which your cable can transfer data (2.0 vs. 3.2 vs. 4) has no effect on charging speeds.  Instead, the rating of your cable, your phone’s capabilities and the charging source all play a significant role in your charging speed.

The two primary flavors of wattage in USB-C cables are 60W and 240W.  Generally speaking, a 60W cable will cover you up to 60W while a 240W cable is required above 60W.  The overwhelming majority of USB-C cables sold in the US are 60W cables.  The reason for this is a function of cost, 240W cables are significantly more expensive than 60W cables, and the charging constraints of phones and chargers, many of which do not charge above 60W.

As of September 2023, the fastest-charging phones in the US are the Samsung S23 Ultra, which uses Samsung Fast Charge 2.0 to charge at 45W, and Oneplus, which charges at 65W.  Both of these devices only reach their max charging speed with a 240W cable and a charger that produces the corresponding wattage or higher.

Outside of these two models, most phones sold in the US max out under 30W.  As an example, Apple’s iPhone 14 maxes out at 27W with the iPhone 15 expected to have similar capabilities. As a result, a regular USB 60W cable, with the ability to handle up to 60W, has more than enough juice to support a majority of phones in the US.

Instead of the cable it is your charging source that largely determines how fast your phone will charge.  The standard Apple wall charger (aka “the white brick”) that previously came with iPhones charges at 5W.  Most charging supply companies, like Ventev and our 30W GaN Mini Charger, now offer options that charge at 20W or 30W, which are 4x and 6x faster than the standard 5W brick.    

In short, if you are interested in only charging speed, don’t fret about the changes with the iPhone 15.  Almost any USB-C cable will get you where you need to go.  Instead, do some research on your phone and find the right charger to maximize your charging speed. 

Data Transfer Implications

If you are interested in data transfer, the difference between the types of USB-C will make a difference.  But what are the implications of the different data transfer speeds?  Ultimately, it will depend on the amount of data you intend to transfer over the cable.  Here is a quick summary of the types of use case that may be best for each flavor.  Keep in mind your cable is a medium and that the devices you are using may present data transfer constraints:



Target Usage



Everyday transfers (photos, videos, etc.)


Up to 20Gbps

Transferring 4K or hi-res videos, using a hi-res or audio set up, using high end computer accessories (external hard drives) or multi-port hubs, using 4K displays


Up to 80Gbps

Transferring 4K or hi-res videos, using 8K displays, running multiple hi-res monitors, using high end computer accessories (external hard drives) or multi-port hubs



Although the change to USB-C on the iPhone 15 will cause some confusion in the appropriate cable to choose, knowing some fundamentals will help guide you in the right product selection.  For charging, almost any USB-C 60W cable (like our Alloy cable with 2x the copper for faster charging) will have you covered.  For data transfer, the choice between USB 2.0, 3.2 and 4 will be largely dependent on your anticipated use of the cable.