Zend vs Yii vs CI for a Social Networking Website

Use what you're comfortable with. That's the most important thing... There's no sense using a tool you don't understand since you won't be nearly as productive (among other issues)...

I have used both Yii and Zend framework and I still use bits of both however. There are some really elegant solutions in yii. I started using Zend framework but have since swinched to use primarily yii, with sprinklings of Zend.

• Yii's component based model is excellent.
• Jquery and ready to go jquery based components out of the tin is a huge time saver.
• not to mention gii which autogenerates whole areas of the application from the database structure.

In my opinion there is no right or wrong in this case. You should choose the framework you can develop best yourself. The better you know, the better and more performant your application will be. It is possible to write fast and slow with every framework. So in your case it is absolutly ok to choose Zend. Keep in mind that most of the framework have their own benchmark where it is praised as the best performing solution ;)