新配的电脑，安装ubuntu16.04以后，出现画面延迟的问题，尤其浏览网页的时候画面十分卡顿。用free命令查看过可用内存6.多G，经过询问大概是显卡问题，然后在https://ubuntuforums.org/showthread.php?t=2377324 找到了答案，尝试了两种方法：

方法一：

Here is the solution for anyone that wants to run Ubuntu on CoffeeLake integrated graphics:
Make sure you're running Ubuntu 17.10 and everything is updated.

Install the latest video drivers:

Code:

sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt-get update

Update the kernel parameter. I used Grub Customizer to do it:

Code:

sudo add-apt-repository ppa:danielrichter2007/grub-customizer 
sudo apt update 
sudo apt install grub-customizer

Launch grub customizer, go to the General tab, and enter i915.alpha_support=1 under Kernel Parameters.

Reboot.

方法二：

I didn't add the oibaf repository and have successfully got 4K output by just editing /etc/default/grub, changing the line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.alpha_support=1"

Then run 'sudo update-grub'
and reboot.