On the Zend Developer Zone today Sam Hennessy has posted some information about how the IBM Power Systems can help you and your PHP application both perform better and do it for less.
If you're from the LAMP world, the concept of vertically scaling with a system like the i5 (IBM Power Systems) will be a complete revelation. If you follow the vertical scaling methodology, when it comes time to design how your application will scale, there is nothing for you to do.
With the i5 series all of the software runs locally and can be optimized for the best performance ("reduced complexity"). Virtual machines on the same physical machine make it quick and easy to create separate environments (like QA or staging). The system does a lot of the common maintenance tasks itself and could require less attention from the IT admins. You can find out more information about these machines from the IBM website.