# Gigabyte M27Q X USB control
[Gigabyte M27Q X](https://www.gigabyte.com/Monitor/M27Q-X-rev-20) can be
controlled via USB with the Gigabyte OSD Sidekick (Windows-only). `m27qx`
implements a subset of its features in a command line tool.
Note: You must be connected to the monitor with the USB cable.
## Setup
If you are on linux, you must allow access to the monitor's USB HID device to
the currently logged in local user:
```bash
sudo cp udev/50-M27Q-X.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules
sudo udevadm trigger
```
Compile and install the tool:
```bash
cargo install --path .
```
## Usage example
```
m27qx --picture-mode=fps
```
## Alternatives
The monitor can also be controlled over DDC/CI (which works without a USB
connection). You can use `ddcutil`, with a less convenient syntax:
```bash
# Set brightness to 50%
ddcutil --model='M27Q X' setvcp 10 50
```
However, some of the features are exposed via a vendor extension `0xe0` which
requires 3-byte values. `ddcutil` is limited to one or two bytes.