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IBM 4381 processors

Introduction: February 1986

The IBM 4381 Processor Model Groups (MG) 21, 22, 23 and 24 bring expanded performance to the 4381 processor product line. They provide a performance improvement of up to 30 percent over current models, and greater price performance. A wide variety of upgrade options is available for customers - enhancing their investment in System/370 software, hardware, applications and training.

The IBM 4381 Processor is a high-end, mid-range processor with a performance range between the IBM 9370 Information System and the IBM 3090 processor family. The 4381 can be used for general purpose commercial applications, as well as specialized applications requiring complex mathematical operations. It is IBM's entry-level processor series that supports Extended Architecture (XA).

Highlights:
- New technology: use of IBM's newest one megabit memory chip technology in MG22, MG23 and MG24; a denser memory technology which allows increased memory capacity and faster processing.
- Increased memory: double the memory capacity in the processor line by offering up to 64 megabytes (MB) in the MG23 and MG24.
- More upgrade options: upgrades within the newly-announced MG21-24; from the Model Groups 11 through 14 to the new processors; and from the original Model Groups 1 through 3.
- Performance growth: six-fold performance growth from the entry-level Model Group 11 through Model Group 24.
- Faster processor cycle times: 52 nanoseconds in Model Groups 23 and 24.
- More high-speed channels: Additional high-speed (3MB/second) channels on the MG21, 23 and 24.
- Connectivity: Serial Original Equipment Manufacturer Interface (SOEMI) attachment capability, providing connectivity between the 4381 host processor and OEM subsystems.
- Wide array of operating systems: VM, MVS, VSE, IX/370, TPF, OS/VS1 as well as MVS/XA, VM/XA and VM/HPO.
- New performance assist feature: 15 percent performance increase for Interactive Executive/370 (IX/370) microcode support.
- Preferred Machine Assist (PMA): 10-30 percent performance improvement for VSE/SP running as a guest operating system under Virtual Machine/System Product (VM/SP) High Performance Option.
- Enhanced Compute-Intensive Capability.
- Installation Flexibility: Air cooled to allow customer installation either in data processing centers or in the work areas.
- High Reliability.

The internal throughput rates have been estimated and compared to similar measurements for the Model Groups 11 through 14. IBM customers can expect significant performance gains of up to 30 percent for commercial applications when upgrading to the new 4381 processor model groups. The following are sample performance increase percentages.

Model Group 21:
- A uniprocessor that is approximately 30 percent more powerful than the entry-level Model Group 11.
- Double the minimum memory of the Model Group 11, with memory capacities of eight and 16MB.
- High-speed buffer storage: 8KB.
- Cycle time: 68 nanoseconds (ns).
- Six standard and six optional channels.
- Additional 3MB/second data streaming channel capability.
- Availability: First quarter 1988.
- Price: $225,000.
Model Group 22:
- An intermediate level uniprocessor.
- Memory capacity: 16, 32MB.
- High-speed buffer storage: 32KB.
- Cycle time: 68ns.
- Six standard and six optional channels.
- Availability: First quarter 1988.
- Price: $350,000.
Model Group 23:
- A high-end uniprocessor with memory up to 64 megabytes (MB) that is 30 percent more powerful than the Model Group 13.
- Memory capacity: 16, 32, 48, 64MB.
- High-speed buffer storage: 64KB.
- Cycle time: 52ns.
- Six standard and six optional channels.
- Additional 3MB/second data streaming channel capability.
- Availability: First quarter 1988.
- Price: $530,000.
Model Group 24:
- A high-end dual processor with memory up to 64MB that is 30 percent more powerful than the Model Group 14.
- Memory capacity: 16, 32, 48, 64MB.
- High-speed buffer storage: 2 buffers, each 64KB.
- Cycle time: 52ns.
- 12 standard and 6 or 12 optional channels.
- Additional 3MB/second data streaming channel capability.
- Availability: First quarter 1988.
- Price: $890,000.

Source: IBM Information Systems Group press fact sheet distributed on May 19, 1987.