Lorna Mitchell has a new post today showing you how to install XHGui to help with profiling your application for performance and processing issues.
If you're not familiar with XHGui it's a fabulously easy and friendly way to profile your application; to understand which method calls in a page take the time and how many times they are made, so you can improve the performance of your application. All these instructions are for my 32-bit Ubuntu 12.10 system, hopefully they will work for you or you'll be able to adapt them as appropriate.
She lists the dependencies you'll need to have installed before you can get XHGui working correctly including a MongoDB instance and the PECL xhprof extension. With those all set to go, you can go grab the latest XHGui from github and drop it into place.