# Supercomputing in India

Supercomputing in India has a history going back to the 1980s. The Government of India created an indigenous development programme as they had difficulty purchasing foreign supercomputers. As of November 2024, the AIRAWAT supercomputer is the fastest supercomputer in India, having been ranked 136th fastest in the world in the TOP500 supercomputer list. AIRAWAT has been installed at the Centre for Development of Advanced Computing (C-DAC) in Pune.

## History
### Early years

India had faced difficulties in the 1980s when trying to purchase supercomputers for academic and weather forecasting purposes. In 1986 the National Aerospace Laboratories (NAL) started the Flosolver project to develop a computer for computational fluid dynamics and aerospace engineering. The Flosolver MK1, described as a parallel processing system, started operations in December 1986.

### Indigenous development programme

In 1987, the Indian government had requested to purchase a Cray X-MP supercomputer; this request was denied by the United States government as the machine could have a dual use in weapons development. After this problem, in the same year, the Government of India decided to promote an indigenous supercomputer development programme. Multiple projects were commissioned from different groups including the Centre for Development of Advanced Computing (C-DAC), the Centre for Development of Telematics (C-DOT), the National Aerospace Laboratories (NAL), the Bhabha Atomic Research Centre (BARC), and the Advanced Numerical Research and Analysis Group (ANURAG). C-DOT created "CHIPPS": the C-DOT High-Performance Parallel Processing System. NAL had started to develop the Flosolver in 1986. BARC created the Anupam series of supercomputers. ANURAG created the PACE series of supercomputers.

### C-DAC First Mission

The C-DAC was created at some point between November 1987 and August 1988. C-DAC was given an initial 3 year budget of Rs 375 million to create a 1000MFLOPS (1GFLOPS) supercomputer by 1991. C-DAC unveiled the PARAM 8000 supercomputer in 1991. This was followed by the PARAM 8600 in 1992/1993. These machines demonstrated Indian technological prowess to the world and led to export success. Param 8000 was replicated and installed at ICAD Moscow in 1991 with Russian collaboration.

### C-DAC Second Mission

The PARAM 8000 was considered a success for C-DAC in delivering a gigaFLOPS range parallel computer. From 1992 C-DAC undertook its "Second Mission" to deliver a 100 GFLOPS range computer by 1997/1998. The plan was to allow the computer to scale to 1 teraFLOPS. In 1993 the PARAM 9000 series of supercomputers was released, which had a peak computing power of 5 GFLOPS. In 1998 the PARAM 10000 was released; this had a sustained performance of 38 GFLOPS on the LINPACK benchmark.

### C-DAC Third Mission

The C-DAC's third mission was to develop a teraFLOPS range computer. The PARAM Padma was delivered in December 2002. This was the first Indian supercomputer to feature on a list of the world's fastest supercomputers, in June 2003.

### Development by other groups in the early 2000s

By the early 2000s it was noted that only ANURAG, BARC, C-DAC and NAL were continuing development of their supercomputers. NAL's Flosolver had 4 subsequent machines built in its series. At the same time ANURAG continued to develop PACE, primarily based on SPARC processors.

### 12th Five Year Plan

The Indian Government has proposed to commit US$2.5 billion to supercomputing research during the 12th Five-Year Plan period (2012–2017). The project will be handled by Indian Institute of Science (IISc), Bangalore. Additionally, it was later revealed that India plans to develop a supercomputer with processing power in the exaflops range. It will be developed by C-DAC within the subsequent five years of approval.

### National Supercomputing Mission

In 2015 the Ministry of Electronics and Information Technology announced a "National Supercomputing Mission" (NSM) to install 73 indigenous supercomputers throughout the country by 2022. This is a seven-year program worth $730 million (Rs. 4,500 crore). Whilst previously computer were assembled in India, the NSM aims to produce the components within the country. The NSM is being implemented by C-DAC and the Indian Institute of Science.
The aim is to create a cluster of geographically distributed high-performance computing centers linked over a high-speed network, connecting various academic and research institutions across India. This has been dubbed the "National Knowledge Network" (NKN). The mission involves both capacity and capability machines and includes standing up three petascale supercomputers.
The first phase involved deployment of supercomputers which have 60% Indian components. The second phase machines are intended to have an Indian designed processor, with a completion date of April 2021. The third and final phase intends to deploy fully indigenous supercomputers, with an aimed speed of 45 petaFLOPS within the NKN.
By October 2020, the first assembled in India supercomputer had been installed. The NSM hopes to have the manufacturing capability for indigenous production by December 2020.
A total of 24.83 petaFLOPS of High Performance Computing (HPC) machines were put into service between 2019 and 2023. In addition to 5,930 specialists from more than 100 institutes using the newly constructed facilities, 1.75 lakh (175,000) people received training in HPCs. A total of 73.25 lakh (7.325 million) computational high performance queries were run. Seven systems with processing power greater than one petaFLOPS, eight systems with computational capacities between 500 teraFLOPS and 1 petaFLOPS, and thirteen systems with capacities between 50 teraFLOPS and 500 teraFLOPS were installed during this time.

## Rankings
### Current TOP500

As of November 2024 there are 6 systems based in India on the TOP500 supercomputer list.
| Rank | Site | Name | Rmax (PFlop/s) | Rpeak (PFlop/s) |
| 136 | Centre for Development of Advanced Computing (C-DAC) | AIRAWAT – PSAI | 8.50 | 13.17 |
| 188 | Indian Institute of Tropical Meteorology | Arka | 5.94 | 7.40 |
| 189 | National Centre for Medium Range Weather Forecasting | Arunika | 5.94 | 7.40 |
| 268 | Indian Institute of Tropical Meteorology | Pratyush (Cray XC40) | 3.76 | 4.01 |
| 400 | Indian Institute of Tropical Meteorology | Arka AI/ML | 2.70 | 3.75 |
| 431 | National Centre for Medium Range Weather Forecasting | Mihir (Cray XC40) | 2.57 | 2.81 |

### India's historical rank in TOP500

Rank of Indian supercomputers in TOP500 list :
| List | Number of systems in TOP500 | System Share (%) | Total Rmax (Gflops) | Total Rpeak (Gflops) | Cores |
| 2020 June | 2 | 0.4 | 6,334,340 | 6,814,886 | 202,824 |
| 2019 November | 2 | 0.4 | 6,334,340 | 6,814,886 | 202,824 |
| 2019 June | 3 | 0.6 | 7,457,490 | 8,228,006 | 241,224 |
| 2018 November | 4 | 0.8 | 8,358,996 | 9,472,166 | 272,328 |
| 2018 June | 5 | 1 | 9,078,216 | 10,262,899 | 310,344 |
| 2017 November | 4 | 0.8 | 2,794,753 | 3,759,153 | 107,544 |
| 2017 June | 4 | 0.8 | 2,703,926 | 3,935,693 | 103,116 |
| 2016 November | 5 | 1 | 3,092,368 | 4,456,051 | 133,172 |
| 2016 June | 9 | 1.8 | 4,406,352 | 5,901,043 | 204,052 |
| 2015 November | 11 | 2.2 | 4,933,698 | 6,662,387 | 236,692 |
| 2015 June | 11 | 2.2 | 4,597,998 | 5,887,007 | 226,652 |
| 2014 November | 9 | 1.8 | 3,137,692 | 3,912,187 | 184,124 |
| 2014 June | 9 | 1.8 | 2,898,745 | 3,521,915 | 169,324 |
| 2013 November | 12 | 2.4 | 3,040,297 | 3,812,719 | 188,252 |
| 2013 June | 11 | 2.2 | 2,690,461 | 3,517,536 | 173,580 |
| 2012 November | 9 | 1.8 | 1,291,739 | 1,890,914 | 90,548 |
| 2012 June | 5 | 1 | 787,652 | 1,242,746 | 56,460 |
| 2011 November | 2 | 0.4 | 187,910 | 242,995 | 18,128 |
| 2011 June | 2 | 0.4 | 187,910 | 242,995 | 18,128 |
| 2010 November | 4 | 0.8 | 257,243 | 333,005 | 25,808 |
| 2010 June | 5 | 1 | 283,380 | 384,593 | 30,104 |
| 2009 November | 3 | 0.6 | 199,257 | 279,702 | 23,416 |
| 2009 June | 6 | 1.2 | 247,285 | 333,519 | 33,456 |
| 2008 November | 8 | 1.6 | 259,394 | 368,501 | 37,488 |
| 2008 June | 6 | 1.2 | 189,854 | 275,617 | 32,432 |
| 2007 November | 9 | 1.8 | 194,524 | 303,651 | 34,932 |
| 2007 June | 8 | 1.6 | 45,697 | 86,642 | 10,336 |
| 2006 November | 10 | 2 | 34,162 | 61,520 | 10,908 |
| 2006 June | 11 | 2.2 | 36,839 | 66,776 | 11,638 |
| 2005 November | 4 | 0.8 | 11,379 | 21,691 | 3,354 |
| 2005 June | 8 | 1.6 | 13,995 | 24,726 | 4,212 |
| 2004 November | 7 | 1.4 | 6,945 | 11,873 | 2,126 |
| 2004 June | 6 | 1.2 | 5,652 | 9,557 | 1,750 |
| 2003 November | 3 | 0.6 | 2,099 | 5,098 | 1,106 |
| 2003 June | 2 | 0.4 | 1,158 | 3,747 | 822 |