# XP/S35
**Wikidata**: [Q69780854](https://www.wikidata.org/wiki/Q69780854)  
**Source**: https://4ort.xyz/entity/xp-s35-q69780854

## Summary
XP/S35 is a supercomputer manufactured by Intel featuring 512 processor cores, achieving peak performance of 26 gigaflops and sustained performance of 15.2 gigaflops during the mid-1990s. It operated on the OSF/1 and Tru64 UNIX operating systems, representing an important advancement in high-performance computing infrastructure during that era.

## Key Facts
- **Instance of**: Supercomputer  
- **Manufacturer**: Intel  
- **Operating system**: OSF/1 (Unix variant by Open Software Foundation) and Tru64 UNIX  
- **Top500 system ID**: 728  
- **Computer performance**:  
  - Rmax: 15.2 gigaflops (June 1996, November 1996, June 1997, November 1997, June 1998)  
  - Rpeak: 26 gigaflops (June 1996, November 1996, June 1997, November 1997, June 1998)  
- **Number of processor cores**: 512  
- **Related manufacturer**: Intel (founded July 18, 1968, U.S. headquarters in Santa Clara)  
- **Related OS**: Tru64 UNIX (inception: January 1, 1992, United States)  

## FAQs  
### Q: What was the primary use of the XP/S35 supercomputer?  
A: XP/S35 served as a high-performance computing system for complex scientific and technical workloads, utilizing its 512 cores to deliver substantial computational power in the mid-1990s.  

### Q: How did XP/S35 compare to other supercomputers of its time?  
A: With a peak performance of 26 gigaflops, XP/S35 ranked among the world's most powerful systems (Top500 ID 728), outperforming many contemporaries while using industry-standard Intel processors and Unix-based operating systems.  

### Q: Which operating systems did XP/S35 utilize?  
A: XP/S35 ran on OSF/1—a Unix variant developed by the Open Software Foundation—and Tru64 UNIX, a Unix-based operating system originating in the United States in 1992.  

### Q: What hardware defined XP/S35's architecture?  
A: XP/S35 was built around 512 processor cores from Intel, enabling its high-performance capabilities and making it a notable parallel computing system of its generation.  

## Why It Matters  
XP/S35 exemplifies the evolution of supercomputing in the 1990s, bridging the gap between early parallel systems and modern high-performance infrastructure. Its consistent Rmax performance (15.2 gigaflops) across multiple years demonstrated the reliability of clustered computing architectures using commodity Intel hardware and standardized Unix operating systems. By establishing benchmarks in computational density and scalability, XP/S35 influenced subsequent supercomputer designs and contributed to advancements in scientific modeling, where sustained performance stability is critical for complex simulations.  

## Notable For  
- Sustained high performance with Rmax of 15.2 gigaflops across five benchmark periods (1996-1998).  
- Utilization of 512 processor cores, showcasing parallel processing capabilities in the mid-1990s.  
- Integration of OSF/1 and Tru64 UNIX, reflecting industry adoption of standardized Unix-based HPC operating systems.  
- Recognition in the Top500 supercomputer rankings (system ID 728), confirming its global competitiveness.  
- Manufacturing by Intel, highlighting the company's early expansion into high-performance computing beyond consumer chips.  

## Body  
### Technical Configuration  
- **Core architecture**: 512 processor cores provided parallel computing capability.  
- **Processing power**:  
  - Rmax (sustained performance): 15.2 gigaflops  
  - Rpeak (theoretical maximum): 26 gigaflops  
- **Performance consistency**: Maintained identical metrics across measurements on June 1, 1996; November 1, 1996; June 1, 1997; November 1, 1997; and June 1, 1998.  
- **Operating systems**:  
  - OSF/1: Unix variant developed by the Open Software Foundation.  
  - Tru64 UNIX: Primary OS with U.S. inception date of January 1, 1992.  

### Manufacturer and Ecosystem  
- **Intel**: U.S.-based technology company (founded July 18, 1968; headquarters Santa Clara, California) responsible for hardware design and supply.  
- **Open Software Foundation**: Developer of OSF/1, a foundational Unix variant integrated into XP/S35.  
- **Tru64 UNIX**: Operating system optimized for high-performance environments, adopted for XP/S35's core workload processing.  

### Historical Context  
XP/S35 emerged during a pivotal phase in supercomputing, as manufacturers transitioned from custom architectures to standardized clusters using commercially available processors. Its inclusion in the Top500 list (system ID 728) underscores its relevance in global computational rankings during the mid-1990s. The system's dual OS support (OSF/1 and Tru64 UNIX) reflects industry efforts to balance compatibility with Unix-based environments while leveraging emerging hardware capabilities.