How to speed up graphics in Virtualbox virtual OS?

Question

Debian

Installed Debian 8 (and 9 separately) in the latest version of VirtualBox, after updating the laptop with RAM (+4GB) and SSD. I expected that the virtual OS would work faster, but somehow not very noticeable. The graphics are very lag, it is naturally impossible to use comfortably. Are there ways to speed this up? Perhaps you need to adjust the video?
I will add that I set up full-screen work according to one manual, but there is no difference either at 1200px or at 1900px.

Answer 1

The graphics in the virtual machine will not work perfectly, since the virtual video card is emulated by the processor. Installing virtualbox-guest-additions and kernel modules in a virtual machine can help.

Answer 2

Do you have virtualization enabled in your BIOS? If not, turn it on. And as Dmitry already said , install virtualbox-guest-additions with modules.