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In pictures: The (mostly) cool history of the IBM ...
Again totally refreshing the mainframe family in 2000 IBM rolled out the eServer zSeries. IBM said it spent two years and $1 billion to develop the machines. IBM said the key to the new mainframe was its multichip module (MCM) -- the densest, most advanced semiconductor and packaging technology in the world. The 5" x 5" x 1/4" module contains 35 chips mounted on 101 layers of ceramic glass connected to 4,226 I/0 pins by 1 kilometer of wire. The main machine ran 2,500 MIPs on 16 processors and if clustered could handle up to 9 billion transactions/day (300 million transactions/day stand alone), IBM stated. In 2003 IBM introduced the z990 and called it "the world's most sophisticated server."
In pictures: The (mostly) cool history of the IBM mainframe