This Oracle Magazine article on Oracle Exadata describes how Oracle delivers the HP Oracle Database Machine and the HP Oracle Exadata Storage Server.
It identifies a major problem faced by businesses: limited performance due to disk throughput bottlenecks as data growth explodes.
The article then goes on to talk about how the HP Oracle Database Machine and its key component, the HP Oracle Exadata Storage Server, is a way to overcome this bottleneck.
Is your data growth doubling, tripling? Have you considered what limits the performance (if any) in your system? is it disk throughput? something else?
What are you considering to address this?