Which utility is used for network throughput testing in Linux?

The utility used for network throughput testing in Linux is iperf. This tool is specifically designed to measure the maximum TCP and UDP bandwidth performance. It works by creating data streams between a client and server and measuring how much data is successfully transmitted over the network within a specified time frame, allowing users to assess network speed and performance efficiently.

iperf provides options to configure various parameters such as the size of the TCP window, the number of parallel connections, and various timeout and delay settings, making it highly configurable for different scenarios and needs. This focus on network performance testing makes it the go-to option for users looking to analyze network throughput and troubleshoot connectivity issues.

While the other mentioned tools have their specific use cases—fio is primarily for I/O performance on storage, IO500 is a benchmark for evaluating storage systems in high-performance computing environments, and IOR is focused on file system I/O performance—none of them is designed specifically for network throughput testing, which is why iperf is the most appropriate choice in this context.