ISROs SAGA (Supercomputer for Aerospace with GPU Architecture)

ISROs SAGA (Supercomputer for Aerospace with GPU Architecture)

Figure 1. SAGA facility, source [1].

A GPU based supercomputer, SAGA (Supercomputer for Aerospace with GPU Architecture) is developed in VSSC, ISRO. SAGA is based on Intel Xeon processors and nVIDIA GPUs. The supercomputer has a theoretical peak performance of 448 TFLOPS (DP). A GPU based Computational Fluid Dynamics (CFD) software  PARAS-3D has been developed in VSSC. PARAS-3D is a major application software running on SAGA, which is used for CFD analysis of launch vehicles (for example, Fig. 2 and 3). The cluster and infrastructure design was carried out in VSSC. Operating system, job scheduler, automated resource and  power manager are also developed in-house. The supercomputer consists of 736 numbers of Intel Xeon processors 736nVIDIA Tesla GPUs. SAGA uses in-house configured Linux Operating System. The 64-bit Linux operating system (OS)for SAGA is configured using LFS (Linux from Scratch) with support for GPUs and InfiniBand. 

Figure 2. Geometry and Grids for a typical problem. [1]

Figure 3. Pressure contour solution for LVM3 using PARAS-3D, source [1].

PARAS-3D is a Cartesian grid based CFD code that has been developed for SAGA. The CFD code was written for GPUs using CUDA programming model provided by nVIDIA. PARAS-3D has about 2.5 lakhs lines of C-code and is one of the most complex applications running on GPUs. The code is extensively used by ISRO and other aerospace organizations in the country. The advantages of PARAS-3D includes fully automatic grid generation, ability to handle complex geometries, interface for CAD geometries, adaptive grid refinement etc.

[1] SUDHAKARAN.G, THOMAS.C.BABU, ASHOK.V, " A GPU COMPUTING PLATFORM (SAGA) AND A CFD CODE ON GPU FOR AEROSPACE APPLICATIONS".