I have a 3TB Western Digital My Book that I use to store all of my media. I have had it for almost 3 years and have only moved it a handful of times, and because the drive is only accessed on occasion, it hasn't gotten a whole lot spin time. I recently transfered about 40GB of data to the drive and noticed that, on occasion, the drive would click rapidly and the speed of data transmission would slow down. After a few seconds, it would stop and continue to write at normal speeds. It did this maybe once every 10GB or so.

After all of the data was written, I took a look at the S.M.A.R.T information in CrystalDiskInfo. The health status was labeled "Caution," noting that the Reallocated Sectors Count and Current Pending Sector Count were both at 200. Confused, I ran a sector analysis scan using HDD Regenerator, and while it found 140 delays (which I consider nothing), there were absolutely no bad sectors found.

Now, I did defragment the drive a few months ago using O&O Defrag Professional. I had previously erased a large portion of data, so there was at least a 40-50% degree of fragmentation. I am wondering if this possibly caused the issue with the SMART drive information. Should I be worried about this?

Back to the main issue I'm worried about: the drive head. That clicking didn't sound very pleasant. Should I be worried about the drive head going bad?

  • 2
    Unless you show us the entire SMART status, this question cannot be answered reliably.
    – Daniel B
    Jul 20 '15 at 6:29
  • Running O&O Defrag Professional didn't damage your HDD. Your HDD is starting to fail, while the act of running it again won't physically damage it, you could lose access to your data. You should replace the HDD as quickly as possible, perform as little write/reads as possible to device, until you are ready to backup your data.
    – Ramhound
    Jul 20 '15 at 12:13

Back up your data. Brace for a crash.
(You should already be backing up important data in the first place.)

What Your Symptoms Mean

As suggested in this comment, we can best answer your question if you provide the full output of the S.M.A.R.T. attributes. You did provide other information that we can use to guess the condition of your drive, though.

I didn't find or look hard enough to find the manufacturer specification with detailed information about your specific hard drive (presumably with the model number WDBFJK0030HBK), so we're further limited and can't be sure what you're seeing in S.M.A.R.T.
(See the first paragraph of this answer.)

If S.M.A.R.T. has actually counted reallocated sectors, then some sectors have already been found as bad, and an internal table inside tracked by the hard drive controller has remapped the bad sector to a spare one. If the Reallocated Sectors Count is 200, then bad sectors have been reallocated 200 times.

AcePL noted that it is unlikely that Current Pending Sector Count also has the raw value of 200.

You're probably confusing attribute values with raw values. See this Super User question or the following documentation from Hitachi for the distinction:

9.5.2 Attribute values

Attribute values are used to represent the relative reliability of individual performance or calibration attributes. The valid range of attribute values is from 1 to 253 decimal. Higher attribute values indicate that the analysis algorithms being used by the device are predicting a lower probability of a degrading or faulty condition existing. Accordingly, lower attribute values indicate that the analysis algorithms being used by the device are predicting a higher probability of a degrading or faulty condition existing.

If CrystalDiskInfo did label "Caution" on Reallocated Sectors Count and Current Pending Sector Count, then there probably have been remapped sectors and probably are sectors waiting to be remapped. (Further information here)

The reallocation of sectors is transparent to the rest of your computer. You would notice if files become unreadable (as part of sectors that can't be read after repeated attempts) or if you check the S.M.A.R.T. raw value of the Reallocated Sectors Count.

Once your drive runs out of reallocated sectors and writes start failing, S.M.A.R.T. will report an imminent failure. The same goes for failed reads, which you have been fortunate enough not to encounter yet.

Some hard drives (perhaps yours, too) slow down for reads and writes to try to improve the reliability of those operations. This could explain the reduced transfer performance that you observed.

Judging from the HDDRegenerator.Net documentation, it seems that "delays" are HDDRegenerator's way of identifying when the drive slows down for read operations or perhaps where sectors have already been remapped/reallocated.

It's not clear what the clicking sound is. It could be the hard drive struggling with writes kind of like how one would react if their pen were to run out of ink or it could be fragmentation causing the drive heads to seek rapidly.


You're fortunate to have a readable drive. You'd better back up all of your data soon. Make sure only to read from this drive and write to another.

Do not defragment before backing up. Defragmenting will perform both read and write operations on the same drive. Your drive may find bad sectors while writing or cause additional damage if there is debris floating around inside the drive.

Additional Information: Anecdotes

This Super User answer shows read errors on 24 May 2015. The drive worked fine after remapping unreadable sectors, but on 19 July 2015 during a massive write operation, its condition rapidly deteriorated as the drive controller realized that it couldn't write to many sectors. This is why I advise that you do not defragment because unwritable sectors can be lurking and outnumbering the spare sectors built into your drive.

On 01 April 2012, I noticed an input-output error on my 640GB laptop hard drive. I didn't have any S.M.A.R.T. monitoring set up at the time and was a novice at hard drive problems, so the issue crept up on me. A few months later, I made a Super User answer about general slow hard drive troubleshooting using that 640GB hard drive as an example.

On 25 December 2010, my previous laptop hard drive failed and started making a rapid clicking noise. About 5-6GiB of data became completely inaccessible, suggesting that a reading head began moving out of specification. From then on, unexpected clicking noises have been scary to me, which is the initial reason why I strongly suggest making a backup as soon as possible.


What you shared with us were, in all probability, threshold values, and not actual values... Unfortunately it's very easy to mix those two values.

Unless it showed those thresholds already exceeded. But both by identical 200? Not bloody likely.

Those two counts are critical. However, reallocated sectors count is being done on the fly and is considered normal part of drive operations (this means that drive controller found certain number of sectors bad and moved them to spare area - that's why spare sectors are on the drive).

Now, current pending sectors is what's important - but again: raw value, not threshold. You have to monitor closely now. If this value increases, drive is on it's way out. That's why it's a good idea to have software that monitors drive status continuously, so it can show you rate of change over time. My personal choice is HDSentinel, but any similar will do.

As Deltik advises, back up data ASAP. However, it does not necessarily mean crash will come. It is, at this point, more likely than not, but I've encountered drives with way more issues reported, that were otherwise stable.


I agree with @Deltik conclusion, but not entirely what he surmises. S.M.A.R.T is meant to predict failures - the problem it does not do a particularly good job of it. Its possible the drive will last some time (more then 8 weeks), but is unhappy and broken.

The prudent thing to do is to replace the drive and move the data onto the new drive.

Assuming the data on the drive is not highly private (ie could get you into big trouble if someone gets it) You should also check the warranty on your drive - in some places some MyBook drives have a 3 Year warranty. Before sending it back for replacement, back up your data and zero the drive - this will delete most stuff, but not everything - and could also assist your warranty claim by making the issue more visible - of-course this doesn't apply if you don't have a 3 year warranty or strong consumer laws.

  • As David explains S.M.A.R.T data only can predict failures it was designed to predict. It isn't good at predicting a mechanical failure, but mechanical failures, often cause other problems it can detect. If the data needs to be deleted before you send it for warranty, do it before the drive is unreadable, because that happened to me. Even Spinrite couldn't rescue that drive.
    – Ramhound
    Jul 20 '15 at 12:20

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