The underlying data structure for AX is gigantic, as many of us have become intimately aware. As such, performance tuning is always something on the mind of those who administer the ERP system. Better performance = better experience for your end users.
One great way to help with performance is caching. AX 2012 has a lot of options for caching, including Entire Table caching, record level caching, and the SysGlobalObjectCache or SGOC for short.