# XP/S5
**Wikidata**: [Q69816149](https://www.wikidata.org/wiki/Q69816149)  
**Source**: https://4ort.xyz/entity/xp-s5-q69816149

## Summary
The XP/S5 is a supercomputer manufactured by Intel. It utilizes 66 processor cores and operates on the OSF/1 operating system. The system achieved a peak performance of 3.3 gigaflops during its operational period in the mid-1990s.

## Key Facts
- **Classification:** The XP/S5 is a supercomputer.
- **Manufacturer:** The system was produced by Intel, an American multinational technology company.
- **Operating System:** It runs on OSF/1, a variant of the Unix operating system developed by the Open Software Foundation.
- **Processor Cores:** The system contains 66 processor cores.
- **Performance (Rpeak):** It has a theoretical peak performance of 3.3 gigaflops.
- **Performance (Rmax):** The system achieved a maximum sustained performance (Rmax) of 2.06 gigaflops as of June 1995.
- **Top500 Identifier:** The system holds the Top500 system ID 855.

## FAQs
### Q: Who manufactured the XP/S5 supercomputer?
A: The XP/S5 was manufactured by Intel, a major American technology company headquartered in Santa Clara, United States.

### Q: What operating system does the XP/S5 use?
A: The XP/S5 runs on OSF/1, which is a variant of the Unix operating system developed by the Open Software Foundation.

### Q: What was the processing power of the XP/S5?
A: The XP/S5 had a theoretical peak performance (Rpeak) of 3.3 gigaflops and a measured maximum performance (Rmax) of 2.06 gigaflops recorded in June 1995.

## Why It Matters
The XP/S5 serves as a historical example of Intel's involvement in the high-performance computing (HPC) sector during the mid-1990s. While Intel is often recognized for its commercial microprocessors, the XP/S5 demonstrates the company's capacity to deliver integrated supercomputer systems capable of gigaflop-scale processing. 

The system is significant for its use of the OSF/1 operating system, highlighting the industry's reliance on Unix variants for scientific and computational workloads before the widespread dominance of Linux in supercomputing. With 66 processor cores, the XP/S5 represents the parallel processing architectures of its era, which were essential for achieving computational speeds that single processors could not reach. Its inclusion in the Top500 list (ID 855) confirms its status as a competitive, high-end computing resource during 1994 and 1995, contributing to the landscape of research and development capabilities of that time.

## Notable For
- **Intel Supercomputing:** It is a distinct example of a supercomputer built directly by Intel, distinguishing it from systems that merely utilized Intel chips but were assembled by other vendors.
- **OSF/1 Implementation:** It is notable for running OSF/1, a specific Unix variant developed by the Open Software Foundation, reflecting the diverse operating system ecosystem of 1990s supercomputing.
- **Top500 Ranking:** The system is recorded in the prestigious Top500 list with system ID 855, marking it as one of the world's fastest computers during its operational lifetime.
- **Gigaflop Performance:** It achieved a performance milestone of over 2 gigaflops in sustained performance (Rmax) and 3.3 gigaflops in peak performance (Rpeak).

## Body

### System Specifications
The XP/S5 is classified as a supercomputer. It was designed and manufactured by Intel, a prominent organization in the semiconductor industry. The hardware architecture relies on 66 processor cores to execute computational tasks.

### Operating Environment
The software environment of the XP/S5 is built around OSF/1. This operating system is a variant of Unix and was developed by the Open Software Foundation. The choice of OSF/1 aligns the XP/S5 with the standards of open systems software prevalent in high-end computing at the time.

### Performance History
Performance metrics for the XP/S5 were recorded across several months in 1994 and 1995, consistent with Top500 reporting cycles.

*   **June 1994:** The system recorded an Rmax of 2.06 gigaflops and an Rpeak of 3.3 gigaflops.
*   **November 1994:** The system recorded an Rmax of 2 gigaflops (also cited as 2.06 in other records) and an Rpeak of 3.3 gigaflops.
*   **June 1995:** The system recorded an Rmax of 2.06 gigaflops and an Rpeak of 3.3 gigaflops.

The consistency of the Rpeak at 3.3 gigaflops indicates the theoretical limit of the hardware configuration remained constant, while the Rmax hovered around 2.0 to 2.06 gigaflops, representing the actual achievable speed during benchmark tests.