KMS
also: Kernel Mode Setting, DRM
KMS (Kernel Mode Setting) is a Linux kernel feature that allows the kernel to directly manage video display modes, eliminating the need for a separate X server graphics driver to set resolution and refresh rates.
KMS transfers graphics mode-setting responsibility from user-space display servers (like X11) to the Linux kernel itself. This means the kernel controls video output directly through DRM (Direct Rendering Manager) drivers, enabling faster mode switching and better handling of multiple displays.
Before KMS, the X server had to manage graphics modes separately, which was slow and complicated. With KMS, you can switch resolutions from the console without X running, and the kernel ensures consistent graphics state across different environments.
A practical benefit: you can now see kernel boot messages and a console login prompt at native resolution, and seamlessly switch between virtual terminals at full quality without the flickering or mode changes that older systems experienced.
Most modern GPUs (Intel, AMD, NVIDIA) support KMS through their kernel drivers, making it the standard approach for display management on contemporary Linux systems.