I just upgraded to 12.04. When I press the super key to open the dash, there's a lag of 1-3 seconds before it displays, with no other programs running. (This is similar, but not identical, to the issue described in Dash application search unresponsive at startup about 11.10.) At login time, this lag is up to 10 seconds, and sometimes the dash doesn't respond at all to the super key.
In contrast, the launcher Kupfer immediately responds to its hotkey, in milliseconds, and responds to my typing an application name also in fractions of a second.
Is there a way to load the dash in memory or a RAM disk of some sort to make it more responsive?
Use Compiz config setting manager and go to:
Ubuntu Unity Plugin -> Experimental -> Dash Blur
Setting it to
No blur
improved thing massively for me.The always present problems with Dash performance are ridiculous. If they can't make it snappy, why they use effects at all?!
As for the original question - unfortunatelly you may experience this https://bugs.launchpad.net/ubuntu/+source/linux/+bug/990002 or a simillar bug.
No bugs but still not snappy?
After using Unity for months in a relatively bug-free environment on a dedicated graphics I can say this:
Similar to iain's answer, you can also use Ubuntu Tweak to modify those settings.
no blur
You can also use MyUnity to change the settings for the Dash.
Open up MyUnity, click on the "dash" tab and select "Off" on the "Blur" settings drop down box.
Additionally also experimenting with settings under "launcher" might help.
I had similar troubles. Using the Compiz Config Settings Manager (ccsm) I modified the window fade-in/out values, everything is responding faster.