To take off the Transparency features in Yosemite I have the newest Macbook Air with maximum flash memory and processor power. 
Still, the search functionality lacks i.e. there is a time gap when hitting a button and getting the result in Finder. 
No such gap exists in Terminal. 

How can you take of the new features of Transparency and others which can make my Yosemite faster?
Open up System Preferences.
Click on Accessibility.
Place a checkmark next to Reduce Transparency.


How to Improve OS X Yosemite Performance