In pictures: The (mostly) cool history of the IBM ...
First introduced in 1985, Enterprise System/3090's had over one-million-bit memory chips and featured what IBM called Thermal Conduction Modules to speed chip-to-chip communication times. Some 3090's ran something called a Vector Facility that was designed to "increase the computing performance capability of the central processor when iterative or repetitive logical or floating-point operations are to be performed on many related data elements," IBM stated. Prices for larger models topped $5 million.
In pictures: The (mostly) cool history of the IBM mainframe