I’m looking for a PHP Framework and Yii2 and Laravel both meet my needs.
To help me in my choice, I have few questions:
Will Yii2 have a Long Term Support, and if so how long? (Laravel announced 2 years for bug and 3 years for security).
Does the framework performance (I mean time to display "Hello World" as in your performance benchmark) have a big impact on a site that will mainly display informations like articles, but that could have thousands of visitors at same time. Since I have read that performance is more important for sites like social networks.
The benchmark here is about Yii1.x what about Yii2.x ?
Will I have to update my site each time there is a new version (each 2,3 months) or I can wait for a major release ?
We have not announced it officially but in general even non-LTS versions of Yii are supported way longer than 2 years. 1.1 was actively supported for 7 years and still receive patches for PHP compatibility and security. I think 2.0 will be similar.
Depends on what impact you’re takling about. The more time it takes to load the more CPU and memory are used so you pay more in the end to achieve same performance.
1.1.
You don’t have to update it. Versions which are released each 2-3 moths are not breaking anything. At least intentionally (minor breaks happened accidentally in the past).
You can wait for major releases, if you want to do that.
But, why would you want to do that, I wonder?
Minor releases does not break your stuff, or - if they do (they do that once in a blue moon), the upgrade process is very smooth.
You will want to upgrade because of all the great fixes/improvements, believe me.
Laravel and Yii 2 compares well.
In fact, they are so equal, that you won’t get a definitive answer to your question: which one is better?
So, take your pick.
Pick the one you like the best.
The Great Google will guide you, should you want to actually see some head to head comparisons, but you can also take my word for it: they are pretty much equal.
Edit:
In case your Google Foo sucks, here is one such comparison:
You are right it’s better 
