PHP 7.0 brings you unprecedented levels of real-world performance and throughput by utilizing the new and advanced Zend Engine 3.0, designed and refactored for speed and reduced memory consumption. This translates to real-world benefits: greatly decreased response times, superior user experiences, and the ability to serve more users with fewer servers to maximize the power of your PHP 7.0 deployment.
PHP 7.0 also uses much less memory thanks to the compact data structures and the highly-refactored codebase of Zend Engine 3.0. Memory consumption gains between 30% and 50% are commonly realized, allowing you to serve more concurrent users without adding additional server hardware.
The PHP development team announces the immediate availability of PHP 7.0.0. This release marks the start of the new major PHP 7 series.
PHP 7.0.0 comes with a new version of the Zend Engine, numerous improvements and new features such as
- Improved performance: PHP 7 is up to twice as fast as PHP 5.6
- Significantly reduced memory usage
- Abstract Syntax Tree
- Consistent 64-bit support
- Improved Exception hierarchy
- Many fatal errors converted to Exceptions
- Secure random number generator
- Removed old and unsupported SAPIs and extensions
- The null coalescing operator (??)
- Return and Scalar Type Declarations
- Anonymous Classes
- Zero cost asserts
Source from Zend.com and PHP.net