Performance Comparative Analysis on Garbage First Garbage Collector and Z Garbage Collector

Well-designed garbage collectors for Java are essential for automatic memory management. Garbage First Garbage Collector (G1GC) is the default garbage collector for JVM, and Z Garbage Collector (ZGC) has been the latest-released garbage collector since JDK 11. These two garbage collectors possess distinctive performance based on different environments. Knowing the different features and performance between these two garbage collectors can help developers to make choices according to their own requirements of garbage collection so that developers can carry out better. Meanwhile, there are relatively less comparative studies between G1GC and ZGC at present. Hence, this paper introduces and compares two garbage collectors and runs an object-creation-and-disposal experiment on G1GC and ZGC to examine their performance in the aspects of heap allocation, CPU usage and time consumption on multiple stages on Java 16. Yield that ZGC unexpectedly has higher throughput and longer total execution time than G1GC, and other attributes are in line with expectations. According to the results, ZGC has a better overall performance than G1GC under the testing circumstances.