Why Do Keyboards Have 2 USB Ports?

By Marlo Strydom

Quick Answer: Keyboards have 2 USB ports primarily for increased power demands (RGB lighting, multiple features), USB pass-through functionality, enhanced data transfer speeds, and to ensure reliable operation of all keyboard features.

You've just unboxed your new gaming keyboard and there it is—two USB cables staring back at you. Your first thought might be "Is this a mistake?" or "Do I really need to plug in both?" The sight of dual USB connectors on a keyboard often confuses users, but there's solid engineering reasoning behind this design. Understanding why keyboards have 2 USB ports will help you get the most out of your peripheral and avoid the frustration of features not working properly.

1. Power Requirements

One of the primary reasons some keyboards come with two USB connectors is due to power requirements. Modern mechanical keyboards, particularly those with RGB lighting and additional features like programmable keys or built-in screens, can consume more power than a single USB port can provide.

Power Over USB

  • Standard USB 2.0 Port Power Output: Typically, a single USB 2.0 port provides up to 500 milliamps (mA) of power at 5 volts. For most basic keyboards, this is more than sufficient. However, when you add features like customizable RGB lighting, multiple key switches, or additional onboard memory, the power demand increases.

  • Need for More Power: To ensure that all features work seamlessly, manufacturers often add a second USB connector to draw additional power from another USB port. This ensures that the keyboard functions correctly without issues like flickering lights or unresponsive keys.

2. USB Pass-Through Port

Another common reason for dual USB connectors is the inclusion of a USB pass-through port on the keyboard. This feature allows users to connect another USB device, like a mouse, headset, or USB drive, directly to the keyboard.

Benefits of USB Pass-Through

  • Convenience: Having a USB port on your keyboard can be incredibly convenient, especially if your computer tower is under a desk or in a hard-to-reach place. You can plug in devices without reaching for the computer's ports.

  • Maintaining Performance: For aUSB pass-through port to function properly without reducing the keyboard's performance, it requires a separate USB connection to the computer. This second USB connector ensures that the keyboard and the device connected to the pass-through port receive adequate power and data bandwidth.

3. Enhanced Data Transfer Speed

While this is less common, some high-performance keyboards use a second USB connector to enhance data transfer speeds. This is particularly relevant in gaming scenarios where quick keypress registration is crucial.

Why Speed Matters

  • Polling Rate: High-end gaming keyboards often support higher polling rates (e.g., 1000Hz), which means the keyboard reports its status to the computer more frequently. This can improve responsiveness in fast-paced games.

  • Dedicated Data Channels: By using a second USB connector, the keyboard can maintain a dedicated data channel, minimizing any potential delay or interference that might occur if a single USB connection is handling too much data.

4. Future-Proofing

Some manufacturers include a second USB connector for future-proofing. As keyboard technology continues to evolve, having an extra USB connector allows for additional features or upgrades without needing to replace the entire keyboard.

Example of Future Use

Firmware Updates: Some keyboards might require more power or bandwidth for future firmware updates or new features. Having a second USB connection ensures that users won't need to worry about compatibility with these updates.

5. How to Use Keyboards with Two USB Connectors

If you own a keyboard with two USB connectors, it's essential to use it correctly to benefit from all its features:

  • Plug Both USBs: Typically, both USB connectors should be plugged into your computer. The keyboard will usually have labels indicating which connector is for power and which is for data/pass-through.

  • Check Your Ports: Ensure that you're using USB ports that meet the keyboard's requirements. For example, if the keyboard is USB 3.0 compatible, plug it into a USB 3.0 port for optimal performance.

Important: Never force USB connectors into ports. If both cables don't fit easily, check your available ports or consider using a powered USB hub to ensure adequate power delivery to your keyboard.

Getting the Most from Dual USB Keyboards

Dual USB keyboards aren't just a marketing gimmick—they solve real technical limitations. The extra connector ensures your RGB lighting doesn't flicker, your pass-through port works reliably, and your high-polling-rate gaming performance stays consistent. When shopping for keyboards, look for models that clearly label their USB connectors (power vs. data) for easier setup.

Pro Tip: If you're short on USB ports, connect the primary data cable first. Most keyboards will function at reduced capability with just one connection, though you'll lose RGB intensity and pass-through functionality.

Understanding why keyboards have 2 USB ports helps you make informed purchasing decisions and ensures proper setup. Whether you're powering advanced RGB effects, using convenient pass-through ports, or maximizing gaming performance, dual USB connections provide the power and bandwidth modern keyboards need to deliver their full feature set.