When the computer code-named "STRETCH" debuted in 1961, detractors were quick to call it a failure -- even though it performed 30 times faster than the most advanced computer in the world.
Not until 1964 when the System/360 was designated an unqualified success did industry analysts understand how much the mainframe owed to STRETCH, officially named the IBM 7030.
The pioneering computer introduced new concepts, such as the 8-bit character called a "byte," as well as many technologies still used in current high-performance systems.
A litmus test
It was the mid-1950s. IBM needed government funding to develop a new scientific prototype. When word circulated that the U.S. Atomic Energy Commission was interested in a high-performance computer, Stephen Dunwell proposed a system that would deliver 100 times the performance of the IBM 704 data processing system, then the industry's fastest computer. Although that claim would come back to haunt him, it got the executive attention he needed at the time.
In 1956, IBM won the contract to build a system for the Atomic Energy Commission at Los Alamos. A cover letter for the proposal promised "speed at least 100 times greater than that of existing machines."
With that goal in mind, the IBM data systems division coined the term "STRETCH" to challenge every ounce of IBM’s intellectual capacity as far as it could go. The project became a litmus test for the future of IBM computers.
The world's fastest computer — a failure?
During the project, the developers realized that they would have to reduce the clock speeds. This meant that the computer would not meet its aggressive performance goals. When it became apparent that STRETCH would not operate at even 75 times the speed promised, IBM Research at Watson considered it a failure.
IBM reduced the selling price from $13.5 million to $7.8 million — below what it would cost to build the system. Eight units were sold.
The 7030 reigned as the fastest computer in the world until 1964. Yet many of the high-performance concepts initiated by the 1950s STRETCH computer still influence current superscalar microprocessors.
3,000 incandescent lamps glowed a gorgeous orange
Here's how some IBM employees remember the STRETCH project:
"The 7030 consisted of 10 machines, each as big as an outsized refrigerator. On the broad side of the last box, the engineer's console, which incorporated about 3,000 incandescent indicator lamps, glowed a gorgeous orange with the room light turned out. This was still the era when maintenance engineers came with the machine." — Norman Hardy
"This was a very, very early time [in computer development] in '55, '56, '57. Because of the state of the art of that time, a great deal had to be invented in the state of the technology." — Fran Allen, IBM Fellow
"My first STRETCH run was an Eigenvalue problem, which ran about 10 minutes on the 704. The program was entered on punched cards through the card reader. I pushed "Start" and almost immediately after reading the last card, the "halt" light came on. After a half an hour or so of debugging and poking around on the console, we suddenly realized the program had simply completed successfully! My introduction to 7030 performance." — Bob Ramey
Visit the STRETCH collection at the Computer History Museum.
Last updated on September 15, 2008