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:
“My first big mistake was made when, in a moment of weakness, I consented to learn the game; for a man who can frankly say “I do not play bridge” is allowed to go over in the corner and run the pianola by himself, while the poor neophyte, no matter how much he may protest that he isn’t “at all a good player, in fact I’m perfectly rotten,” is never believed, but dragged into a game where it is discovered, too late, that he spoke the truth.”
—Robert Benchley (1889–1945)
“Wilmer Cook: Keep on riding me, they’re gonna be picking iron out of your liver.
Sam Spade: The cheaper the crook, the gaudier the patter.”
—John Huston (1906–1987)