Parallelism in Go and Java : A Comparison of Performance Using Matrix Multiplication

Abstract: This thesis makes a comparison between the performance of Go and Java using parallelizedimplementations of the Classic Matrix Multiplication Algorithm (CMMA). The comparisonattempts to only use features for parallelization, goroutines for Go and threads for Java,while keeping other parts of the code as generic and comparable as possible to accuratelymeasure the performance during parallelization.In this report we ask the question of how programming languages compare in terms of multi-threaded performance? In high-performance systems such as those designed for mathemati-cal calculations or servers meant to handle requests from millions of users, multithreadingand by extension performance are vital. We would like to find out if and how much of a dif-ference the choice of programming language could benefit these systems in terms of parallel-ism and multithreading.Another motivation is to analyze techniques and programming languages that have emergedthat hide the complexity of handling multithreading and concurrency from the user, lettingthe user specify keywords or commands from which the language takes over and creates andmanages the thread scheduling on its own. The Go language is one such example. Is this newtechnology an improvement over developers coding threads themselves or is the technologynot quite there yet?To these ends experiments were done with multithreaded matrix multiplication and was im-plemented using goroutines for Go and threads for Java and was performed with sets of4096x4096 matrices. Background programs were limited and each set of calculations wasthen run multiple times to get average values for each calculation which were then finallycompared to one another.Results from the study showed that Go had ~32-35% better performance than Java between 1and 4 threads, with the difference diminishing to ~2-5% at 8 to 16 threads. The differencehowever was believed to be mostly unrelated to parallelization as both languages maintainednear identical performance scaling as the number of threads increased until the scaling flat-lined for both languages at 8 threads and up. Java did continue to gain a slight increase goingfrom 4 to 8 threads, but this was believed to be due to inefficient resource utilization onJava’s part or due to Java having better utilization of hyper-threading than Go.In conclusion, Go was found to be considerably faster than Java when going from the mainthread and up to 4 threads. At 8 threads and onward Java and Go performed roughly equal.For performance difference between the number of threads in the languages themselves nonoticeable performance increase or decrease was found when creating 1 thread versus run-ning the matrix multiplication directly on the main thread for either of the two languages.Coding multithreading in Go was found to be easier than in Java while providing greater toequal performance. Go just requires the ‘go’ keyword while Java requires thread creation andmanagement. This would put Go in favor for those trying to avoid the complexity of multi-threading while also seeking its benefits.