Some drives also make clicking noises when the drive is starting up from stop during the start up sequence, but these stop when the drive reaches operating speed (typically 5400rpm or 7200rpm). ?This does not sound like the issue you are describing. ?If it is, it is highly indicative of an impending failure and you should replace the drive.

A more common cause for the “clicking” noises drives emit are caused by movements of the arm that holds the heads that read data from the disk (the disk itself is run at constant speed). ?

It is possible that something due to impending failure that is making movement of the pickup arm more noisy (most likely a bearing failure) but this is unlikely - mechanical hard disks are extraordinarily reliable. ?A cloud storage firm produces a report on reliability of drives in its disk-farms each year and typically just under 2% of their disks fail per year (more here -?). ?WD drives always have done OK in those listings.

The other (more likely) cause for the noise is that when reading / writing data to the drive, the heads are just working harder - i.e. having to make more moves of the head to read / write data to the disk itself. ?When the drive is blank a file can be written by staring at a point and writing into the sectors one after the other - so all the read / write head has to do is move to the start point, and then as each sector is written make the small adjustment to the start of the next sector (which will be the nearest empty sector to the one being used). ?Over time, just due to how files get written / deleted, the ’next nearest empty sector’ gets further and further away - getting to the next nearest sector thus requires a bigger movement of the heads. ?This need to move all over the place to read / write a file gets worse over time and is called ‘fragmentation’. ?

There are two ways to fix fragmentation - but unfortunately neither work reliably on USB drives

For USB drives probably the only reliable solutions are either to reset the drive with a manufacturer supplied utility (no idea if such exist for WD), or to write a myriad of very small files to the disk (each smaller than one sector) and then delete them again - this will implicitly reset the disk map and may (probably) will result in future large files being written to serial locations. ?But again this is quite complicated to do, and possibly won’t help.

So if noise is not a good indicators, what is…?

A much better predictor of impending drive failure is to look at the SMART data report most drives now produce - but only if the drive is giving problems (i.e. data you save is getting messed up or lost). ?In particular, if the drive is giving data problems and the “Uncorrectable Sector Count” is going up (one of the many SMART numbers) there is a high probability the drive is going to fail soon. ? SMART stats on drives that otherwise are operating normally are not reliable indicators of impending drive failure.

Getting hold of SMART data itself is not so easy - the disk utility in macos will report a composite number (look for “SMART Status” ?in the panel that appears when you do “get info” on a drive highlighted in disk utility…) for mechanical drives that are directly connected to the mac (i.e. internal drives). ?For USB connected drives you need to get this data via a specific disk utility for USB drives - presumably there is some kind of utility software for WD drives provided by WD - but whether it will give this SMART info or not is dependent upon how they wrote the software.

There is a Windows utility that might do the job - but I don’t know how easy it is for you to plug your drive into a windows machine - if you can the software is here -?

HTH

Gavin