As hot new servers have grabbed more attention, mainframes have been plugging away behind the scenes. For decades, they have been the technological backbone for banking, finance, insurance, defense, health care, education, government and other industries.
"The perception is we're old and gray," said Jim Porell, an engineer who works on mainframes at IBM, the only company that still makes them.
Lately, more software has been written for mainframes, and they support everything from ATMs to Web-hosting to cell phones, not exactly ancient technology.
But while mainframes are evolving to handle more applications, the number of mainframes is shrinking, said John Phelps, the lead mainframe analyst for technology research firm Gartner. IBM has lost more than 75 customers who left mainframe platforms, and it has gained about 50 new ones. Mainframes are operating more efficiently, handling more MIPS -- millions of instructions per second -- year after year.
"The actual number of mainframes has shrunk, but the capacity has gone up," he said. Better efficiency has become more important as users' sensitivity to electrical usage, both for financial and environmental reasons, has increased, he said.