For bulk transfer of many files, and especially transfer over a local/nearby network that may be hold true, but as a general practice, and especially for serial

For bulk transfer of many files, and especially transfer over a local/nearby network that may be hold true, but as a general practice, and especially for serial/one off transfer of very large files, GNU parallel won't help. However, all the tools mentioned multiplex connections. They are better for transferring individual files, and you can also use them in parallel. A combination of your network, a CPU threads, frame size, etc... are your ultimate bottleneck when you are transferring very large files. We've transferred exabytes using bbcp and GridFTP. bbcp is very easy to use once it's set up. At some point, you run into much different issues when trying to routinely transfer very large files across continents at speeds greater than 10Gbps.