Make your hard drive faster
Q
I’m about to start using a new 6TB external hard disk for my Time Machine backups. How can I get best performance from it?
A
If you can afford to set aside a significant proportion of the space on a hard drive, you can partition it so that more active files like your backups are kept in the fastest area on its platter, and store more static files in the slower area. As hard drives spin at constant speeds, and the circumference of their platters is greatest at the outer edge, read and write speeds are highest at that edge, representing the start of the storage, and are lowest at the innermost.
In Disk Utility, format the drive initially into a single APFS volume in one container, the default. Then select the Partition tool and add your reserved partition/container to the end of that, at the upper left of the diagram. For example, if you can set aside 2TB, add a new container with an APFS volume of that size, leaving the first at 4TB. That will place the initial, larger storage area on the fastest two-thirds of the platter.
If the outermost platter reads and writes at 150MB/sec, your backup volume should deliver speeds between around 90-150MB/sec, and the inner 2TB probably around 60-90MB/sec, which is a difference large enough to be noticeable.