php tools to detect bottle neck

I'm developing a web-application with PHP and some libraries. The problem is that i need to generate some excel files, and this 开发者_运维问答procedure takes a lot of time. Can you help me with some tools to identify where my application spends a lot of time,. Can you recommend a php tool which will help me to detect the bottle necks?

ps: the lib that I use for generating the excel files is PHPExcel.

Xdebug or Zend Debugger

They allow you to profile your application and will generate comprehensive lists about which functions have been called and how long they took to execute. XDebug is free. Zend Debugger requires Zend Studio or Eclipse.

See our SD PHP Profiler. This will show you graphically where your code spends most of its time.