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Staff information

Alessandro Morari

Data Sciences


As a research scientist within the Center for Adaptive Supercomputing Software, or CASS, Dr. Morari is part of the PNNL team designing the PNNL Graph Engine for Multi-threaded Systems (GEMS). GEMS is based on the PNNL Global Memory Multi-threaded (GMT), a runtime system Dr. Morari and other scientists designed and developed to efficiently execute irregular applications on large-scale distributed systems.

In addition, Dr. Morari has contributed to several conference papers and journal articles. He has served as a program committee member and as a reviewer for several international conferences.

Prior to joining PNNL, Dr. Morari was a resident student at Barcelona Supercomputing Center and a research intern at the IBM T.J. Watson Research Center.

Research Interests

  • Data-intensive and Irregular applications
  • Semantic Graph Databases
  • Large-scale and Distributed Memory Runtime Systems
  • System Software for High Performance Computing
  • Performance Modeling

Education and Credentials

  • Ph.D. in Computer Architecture, Universidad Politecnica de Catalunya, Spain
  • M.S. in Computer Engineering, Tor Vergata University, Italy

Awards and Recognitions

  • IEEE International Parallel & Distributed Processing Symposium, 2012: Best Paper Award, "Evaluating the Impact of TLB Misses on Future HPC Systems."

PNNL Publications


  • Castellana VG, A Morari, JR Weaver, A Tumeo, DJ Haglin, O Villa, and J Feo. 2015. "In-Memory Graph Databases for Web-Scale Data." Computer 48(3):24-35.  doi:10.1109/MC.2015.74


  • Morari A, A Tumeo, D Chavarría-Miranda, O Villa, and M Valero. 2014. "Scaling Irregular Applications through Data Aggregation and Software Multithreading." In IEEE 28th International Parallel and Distributed Processing Symposium, May 19-23, 2014, Phoenix, Arizona, pp. 1126-1135.  IEEE, Piscataway, NJ.  doi:10.1109/IPDPS.2014.117
  • Morari A, VG Castellana, O Villa, A Tumeo, JR Weaver, DJ Haglin, S Choudhury, and JT Feo. 2014. "Scaling Semantic Graph Databases in Size and Performance." IEEE Micro 34(4):16-26.  doi:10.1109/MM.2014.39
  • Weaver JR, VG Castellana, A Morari, A Tumeo, S Purohit, AR Chappell, DJ Haglin, O Villa, S Choudhury, KL Schuchardt, and JT Feo. 2014. "Toward a Data Scalable Solution for Facilitating Discovery of Science Resources." Parallel Computing 40(10):682-696.  doi:10.1016/j.parco.2014.08.002


  • Chappell AR, S Choudhury, JT Feo, DJ Haglin, A Morari, S Purohit, KL Schuchardt, A Tumeo, JR Weaver, and O Villa. 2013. "Toward a Data Scalable Solution for Facilitating Discovery of Scientific Data Resources." In DISCS-2013: Proceedings of the International Workshop on Data-Intensive Scalable Computing Systems, November 18, 2013, Denver, CO, pp. 55-60.  Association for Computing Machinery , New York, NY.  doi:10.1145/2534645.2534655
  • Morari A, VG Castellana, DJ Haglin, JT Feo, JR Weaver, A Tumeo, and O Villa. 2013. "Accelerating semantic graph databases on commodity clusters." In IEEE International Conference on Big Data (Big Data 2013), October 6-9, 2013, Silicon Valley, California, pp. 768-772.  Institute of Electrical and Electronics Engineers , Piscataway, NJ.  doi:10.1109/BigData.2013.6691650


  • Morari A, A Tumeo, O Villa, S Secchi, and M Valero. 2012. "Efficient Sorting on the Tilera Manycore Architecture." In IEEE 24th International Symposium on Computer Architecture and High Performance Computing (SBAC-PAD 2012), October 24-26, 2012, New York, pp. 171-178.  Institute of Electrical and Electronics Engineers , Piscataway, NJ.  doi:10.1109/SBAC-PAD.2012.41

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