What vocal efx (like auto tune or virtual vocal) does sonar x3 have? Thank you

X3 has melodyne essential included. 

Only X3 Studio and Producer included Melodyne Essential. The basic version of X3 did not.

What is melodyne and is it worth upgrade?

Melodyne is pitch and timing correction software. The essentials version isn't as powerful as the full version.

The main difference is essentials only works on monophonic melodic material. I.e a vocal or single note piano track whereas the full version works on chords and other multiple note material.

It is still a very powerful and useful piece of software though and IMHO well worth the upgrade price.

What effect are you looking for specifically?

david larson
What is melodyne and is it worth upgrade?

If you're thinking about upgrading to X3 that has not been possible for a long time.
I don't know if any DAW includes virtual vocal (?), and IMO it can hardly be called a vocal effect per se. It's more like a soft synth.

Kalle Rantaaho
 
If you're thinking about upgrading to X3 that has not been possible for a long time.

Exactly.  The current Sonar is described here:
 
http://www.cakewalk.com/Products/SONAR
 
The top two versions, Professional and Platinum, include Melodyne Essential.