IBM launched its iconic System/x series with the System/360 in 1964. The series is supported until today with the 64-bit zSeries architecture, which premiered in 2000. The System series also included the System/370 that was launched in 1970 and the System/390, which was introduced in 1990. The first specified processor of the System/360 was the M65MP (Model 65) from 1965. It came with 16 32-bit general purpose registers and supported a 24-bit instruction address. The maximum performance was 750,000 additions per second. The IBM System/370 announcement in 1970 brought the Model 155 and 165 processors with cycle times of 80 and 115 nanoseconds (a cycle is referred to the time it takes to execute an instruction). The 370 saw a great evolution with the 303x, 43xx, 308x, 3090, and 937x series until its cancelation in 1988. Late models improved the cycle time to 68 nanoseconds and included 32 MB of processor storage. The System S/390 introduced 18 different ES/9000 processor models - eight were water-cooled, supported up to 6-way multiprocessing and carried up to 1 GB in memory. The model line has evolved into the zSeries in 2000. Today, IBM is offering the 45 nm z196 flagship mainframe processor with 1.4 billion transistors and clock speeds up to 5.2 GHz.