Big iron, as the hacker's dictionary the Jargon File defines it, "refers to large, expensive, ultra-fast computers. It is used generally for number crunching supercomputers such as Crays, but can include more conventional big commercial IBM mainframes".
The term is often used in reference to IBM mainframes, often when discussing their comeback/survival after the assault of lower cost Unix systems. More recently the term is also applied to powerful computer servers and computer ranches, whose steel racks naturally invoke the same association.
The expression may be compared with the slang expression for heavy handguns, derived from the slang "iron" for a handgun ("shooting iron"), as exemplified by the classic country music ballad Big Iron by Marty Robbins about "the ranger with the big iron on his hip".
Famous quotes containing the words big and/or iron:
“Whenever there’s a big war coming on, you should rope off a big field. And on the big day, you should take all the kings and their cabinets and their generals, put ‘em in the center dressed in their underpants and let them fight it out with clubs. The best country wins.”
—Maxwell Anderson (1888–1959)
“However, there is a locked room up there
with an iron door that can’t be opened.
It has all your bad dreams in it.
It is hell.”
—Anne Sexton (1928–1974)