Mainframes are enjoying a resurgence as companies buy new models to support e-commerce. Many firms are choosing mainframes instead of Windows- and Intel-based server clusters because they offer the availability, scalability and low support costs that Internet business requires.
A mainframe can offer the most computing power currently available for data-centric, as opposed to CPU-centric, business applications. A mainframe looks and acts like one single giant computer, not as a farm of powerful servers, from the point of view of the application and the administrator. That is not to say that a mainframe acts like a single processor: even basic models are optimised for throughput, and Input/Output (I/O) to disk or printer is usually handled by intelligent channels, which are computers in their own right.
