While performances with Unity have increased dramatically since first release users who are using Ubuntu 12.04 LTS are stuck with Unity version 5.x and didn't get performance boost that offers Unity 7.
There are ways you can increase performances with Unity on Ubuntu 12.04.
Before you start make sure you install CompizConfig Setting Manager, you need CompizConfig Setting Manager to make all tweaks
sudo apt-get install compizconfig-settings-manager
Disabling animations
Disabling animations is the first thing you can do to increase performances. This will disable animations for opening, closing and minimizing applications.Open CompizConfig Setting Manager. Navigate to Effects > Animations
Now in tabs Open Animation, Close Animation and Minimize Animation select animations and click delete button.
You can restore animation by clicking restore to default button.
Disabling blur
Disabling blur in Unity can lead to big performance increase and if you are experiencing "lag" when using Unity Dash it will fix this issue.To disable blur open CompizConfig Setting Manager. Navigate to Ubuntu Unity Plugin > Expreimental
There change Dash Blur to No Blur
Running Unity in low GFX mode
Runnig Unity in low GFX mode will disable brur, effects and transparency. Instead manully disabling blur and animations you can use this commands.gedit .xprofile
export UNITY_LOW_GFX_MODE=1
You need to restart comuter to take efect.
Resetting Unity configuration/settings
In some cases resetting configuration setting to default may help. To reset configuration setting to default type following command in terminal:unity --reset
This command only works in Ubuntu 12.04. For Ubuntu 12.10+ you need to to use other command.
First install dconf
sudo apt-get install dconf-tools
dconf reset -f /org/compiz/
unity --reset-icons
Switching to Unity 2D
One solution is to swith to Unity 2D. Depends on your hardware configuration this can dramaticly increase performance.You can switch to Unity 2D by chosing Unity 2D at login screen.