Lynn Wheeler describes the #IBM 3081 #mainframes effort as “quick-and-dirty” in response to the Amdahl threat; he says it was “The 370 emulator minus the FS [Future System] microcode”. Lynn explains, “Amdahl two processor had better throughput than four processor 3084.” #history
on 02025-11-23#IBM 3084QX #performance was 31 MIPS. #mainframes #history
on 02025-11-23#IBM 3084 #mainframes page. #history
on 02025-11-23#IBM 3084 #mainframes cost US$8.7 million in 01983. “The machine uses two model K 3081 Processor Units with 64Kb of fast buffer memory. Each 3081 K Processor Unit is composed of two processors.” As for #performance: “The 3084 was released with either 32, 48 or 64 Mb of memory. The system in the collection has 16 Mb of main memory (because it is half of the entire 3084 system). The memory has a cycle time of 312 nanoseconds and is 8 bytes wide.” So I guess you could read or write main memory at 24 megabytes per second, which suggests a speed around 24 MIPS. #history
on 02025-11-23discussion of #performance of computers that could have been used to design the 80386: “Top of the line VAX in 1984 was the 8600 with a 12.5 MHz internal clock, doing about 2 million instructions per second.
IBM 3084 [mainframe] from 1984 - quad SMP (four processors) at 38 MHz internal clock, about 7 million instructions per second, per processor.” That was when #mainframes were fast, rather than just having a lot of I/O.
on 02025-11-23