Although not one of the more well-known mainframes, when the IBM 3090 was announced in 1985 it offered a solid advancement on the System/370 architecture that not only continued the improvements in speed, but also increased the number of processors while giving them vector processing options.
Initially only available as Model 200 and Model 400 (the first number denoted the number of processors), the line was expanded dramatically in its short four years of existence. A uniprocessor version (1xx series) and a 600 series of processors were added, as well as an enhanced version of each model (denoted with an "E" after the model; for example, 600E). Even the original models were formidable, running at over 54 MHz, and executing instructions almost twice as fast as the 3081s they replaced.
The next year the 3090 was expanded to include the vector processing feature, which added 171 new instructions and sped up computation-intensive programs by a factor of 1.5 to three times. The "E" version of the 3090 ran at a brisk 69 MHz, and was capable of roughly 25 MIPs per processor. By comparison, the x86 processor at that time, the 80386, ran at 20 MHz, was capable of roughly 4 MIPs, was uniprocessor only, and had no vector instructions.
The 3090 was replaced after four short years by the ES/9000 line. With local area networks (LANs) gaining popularity and powerful new processors like the 80486 and the many RISC designs (including IBM's own POWER), it was becoming increasingly clear that these technologies would soon render the mainframe obsolete and extinct, as they were doing to the mini-computer. The handwriting was on the wall for anyone that wanted to read it. Or was it?