dell 服务器 安装Ubuntu ，matrox显卡卡顿问题解决方法

搜索了一下网上的解决方法：
1，
sudo gedit .xprofile
export UNITY_LOW_GFX_MODE=1
发现还是不行。
2，然后看到下面这个，试了一下，解决了。

Same problem with a Dell PowerEdge R720, video card Matrox Electronics Systems Ltd. G200eR2
I try many ways but no one can be work fine with the ubuntu 14.04 ,
when i google the G200eR2’s driver, i found a solution with this card, remove the mga driver!

sudo apt-get remove xserver-xorg-video-mga

it will remove the xserver-xorg-video-mga and xserver-xorg-video-all
then reboot
now the window not slowly, and screen only has a 800x600 @75hz , but it work fine

i hope this way can help other people

或者也可以看原网页
https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1316035