# XP/S20
**Wikidata**: [Q70082321](https://www.wikidata.org/wiki/Q70082321)  
**Source**: https://4ort.xyz/entity/xp-s20

## Summary
The XP/S20 is a supercomputer manufactured by Intel that operates using the OSF/1 operating system. It features 256 processor cores and achieved a maximum recorded performance (Rmax) of 7.6 gigaflops, as recorded between 1995 and 1996.

## Key Facts
*   **Classification:** Supercomputer
*   **Manufacturer:** Intel (American multinational technology company)
*   **Operating System:** OSF/1 (a variant of Unix developed by the Open Software Foundation); also associated with Tru64 UNIX.
*   **Processor Cores:** 256
*   **Performance (Rmax):** 7.6 Gigaflops
*   **Performance (Rpeak):** 12.8 Gigaflops
*   **TOP500 System ID:** 1596
*   **Performance Timeline:** Recorded benchmarks for Rmax and Rpeak are identical across four data points spanning June 1995 to November 1996.

## FAQs
### Q: What type of operating system does the XP/S20 use?
A: The XP/S20 runs on OSF/1, which is a variant of the Unix operating system developed by the Open Software Foundation. It is also classified under the Tru64 UNIX operating system class.

### Q: What are the performance specifications of the XP/S20?
A: The system has a maximum performance (Rmax) of 7.6 gigaflops and a peak performance (Rpeak) of 12.8 gigaflops. These metrics were recorded consistently between June 1995 and November 1996.

### Q: Who manufactured the XP/S20?
A: The XP/S20 was manufactured by Intel, an American multinational technology company headquartered in Santa Clara, United States, known primarily for its work in the semiconductor industry.

## Why It Matters
The XP/S20 represents a specific era of high-performance computing history manufactured by Intel, a company traditionally dominant in the semiconductor industry. Its fixed performance metrics over a multi-year period (1995–1996) provide a stable data point for analyzing the computational standards of supercomputers during the mid-1990s.

The machine is significant for its integration of a 256-core architecture with the OSF/1 operating system, illustrating the reliance on Unix variants for high-end scientific computing during this period. While its speed of 7.6 gigaflops is modest by modern standards, the XP/S20 serves as a historical benchmark for the capabilities of clustered or parallel Intel architectures prior to the turn of the millennium. It highlights the diversification of Intel's product portfolio beyond consumer microprocessors into full-scale supercomputer systems.

## Notable For
*   **High Core Count:** Utilizing 256 processor cores, a significant number for mid-1990s hardware.
*   **Intel Architecture:** Being a supercomputer explicitly manufactured by Intel.
*   **OSF/1 Dependence:** Relying on OSF/1, a distinct Unix variant, rather than more common commercial Unix flavors of the time.
*   **Performance Consistency:** Demonstrating identical Rmax and Rpeak scores across multiple TOP500 list submissions (June 1995, Dec 1995, June 1996, Nov 1996).

## Body
### Technical Specifications
The XP/S20 is classified as a supercomputer. Its architecture is built around **256 processor cores**. The system is identified in supercomputer rankings (TOP500) with the system ID **1596**.

### Performance Metrics
The computer performance of the XP/S20 was measured in gigaflops across four distinct time periods in 1995 and 1996. The metrics remained consistent throughout this timeframe:
*   **Rmax (Max Performance):** 7.6 Gigaflops
    *   Recorded on: 1995-06-01, 1995-12-01, 1996-06-01, 1996-11-01.
*   **Rpeak (Peak Performance):** 12.8 Gigaflops
    *   Recorded on: 1995-06-01, 1995-12-01, 1996-06-01, 1996-11-01.

### Software Environment
The XP/S20 requires a specific Unix-based environment to operate:
*   **Primary OS:** **OSF/1**, a variant of the Unix operating system developed by the Open Software Foundation.
*   **OS Class:** The system is also associated with **Tru64 UNIX**, a 64-bit operating system (formerly known as Digital UNIX) which has its inception dated to 1992.

### Manufacturer
The XP/S20 is produced by **Intel**, a major American technology company in the semiconductor industry. Headquartered in Santa Clara, California, Intel's involvement places the XP/S20 within the lineage of x86 and RISC-based high-performance computing development.