Switching to a virtual terminal is slow

Question

When switching to a virtual terminal using e.g. Ctrl+Alt+F2, it takes about a second to switch. Not too horrible for something that's typically rarely used, but I would like to use it more and it's substantially slower than, say, Alt+Tab. It's particularly weird since switching back to the desktop environment (Alt+F7 for me) is instant.

I've noticed it before, but currently I'm running Debian testing (Stretch) with Cinnamon 2.8.7 on X 1.18.3. The resolution of the virtual terminal is the same as X's resolution.

What is this delay caused by and how can I improve it?

Answer 1

The X server manages the state of the graphics card when it's active. When you switch between X and a text console or back, the graphics card needs to be reinitialized. Depending on the graphics card and on how it's used, there may be an unavoidable delay. A 1s delay is on the high side but not unreasonable.

Few people use a text console, so even if it was possible to improve the transition time (which it might not be), this isn't a high priority for developers.

If this delay is really a problem, try changing the driver or the configuration in X, in text consoles or both. If you're using a proprietary driver, use the free driver, or vice versa. If you're using a framebuffer console, don't, or vice versa. Some options that can affect what needs to be reinitialized when the console switches owners; I don't know what to look for in particular.