WD Black (WD2001FASS) weird Stutter


For some time now I’ve noticed that my WD has begun stuttering occationally. It’s these small interruptions that are very noticeable when streaming from the disk, say playing a game or watching a movie. I can’t describe it accurately, as I clearly don’t know what’s going on, but it seems to me like the the disk has to reposition the heads every now and then, and that leads to the occational stutters which I notice.

There are no errors showing up when testing the drive with WD’s diagnostic tool at all, not even the extended test. Neither when I’ve run other tests, like CrystalDiskMark or HD Tune Pro. The SMART data seems fine too, every disk diagnistic program reports OK next to the smart values.

Like I said, the occational stuttering is very real on this drive, and none of my other drives display this behavior. But if I’m supposed to RMA the disk, I’d like some hard evidence and I’d like to be able to see what’s going on when those stutters occur.

Any ideas on tests that might expose this perceived weakness? And possibly any fix for it?


I’ve noticed the disk operating at 55 C, which is near the 60 C that is specified as the max operating temperature. Could this technically be the reason for the rather occational phenomenon that I’m experiencing?

Hi well when you are playing a movie leave task manager open and when the stutter starts see if anything starts to use more resources if not that would be almost for sure the drive then.

Hmm, I’ve tried keeping the task manager open as you said (windows 8.1) and I don’t really see any difference in the graph when the anomaly occurs.

Can the volume of the data on the disk perpetuate this problem?

Also, I’ve noticed that opening folders often create this small lag when the file manage populates the files. When it happens, it does so regardless of how many files are actually in the folder. I have not seen this sluggish opening of folders on my other drives before, and for a performance-oriented disk, this strikes me as highly suspicious behavior.

Any thoughts on this?

Hi the volume of data would only come into play if there was like 50 meg left on the drive. Try changing the sata cable and see if that helps.

Right, will try switching the sata cable and see if it helps.

Also, would there be any value in completely wiping the disk, as in write 0’s to all sectors?

worric wrote:

Right, will try switching the sata cable and see if it helps.


Also, would there be any value in completely wiping the disk, as in write 0’s to all sectors?

I would also consider getting a utility to check your ram memory to make sure that you are not running into bad memory blocks there also.  How old is your computer.  Also, you could look into your virus protection to see if it’s interfering with the streaming while it does virus checking.  There could be any number of things that may be interferring with the streaming.  I would also look at your event log and see what software is running at those times.

I tried to set the APM mode to disabled via CrystalDiskInfo (or set to FEh, what I assume is disabled APM), and so far I haven’t noticed the same stutters. It seems that my suspicion at the start of the post was confirmed, regarding the head parking. From what I understand, the black series (WD2001FASS) do have the same head parking “problems” as the green series are notorious for, albeit a less agressive implementation.  This post on this forum seems to confirm this.

Accourding to the smart values, the disk has 802 days of operation time, and in that time it has performed 167262 Load/Unload Cycle Count (LCC). During normal operation where the stutters do occur, the LCC climbs steadily; I haven’t timed it myself, but the post I’ve linked states that it happens every 12.8 seconds. Like I said, when the APM is disabled, and the LCC doesn’t climb, the stutters cease.

My findings do suggest, thought, that the head parking has been active all the time, and it pleads the question why I haven’t noticed the stuttering before. I can’t really say. The stuttering has been there for a long time, so it’s possible that I just can’t recall back to when it didn’t. Another possibility is that the disk has some kind of defect that has become pronounced as the LCC’s have ticked in; as I understand, LCC causes wear on the drive, and WD has rated their disks for a certain amount of LCC before malfunction may set in. Maybe my drive has been weak in that regard.

As it is I’m tempted to make CrystalDiskInfo auto-start with windows so as to disable APM completely on boot to eliminate the stuttering.

Seeing as I’ve narrowed the stuttering down to being connected to LCC, does it seem plausible that LCC could cause this stuttering at all? Because if it doesn’t, I’ll most likely RMA the drive.

I got weird stuttering aswell with 500GB WD Blue WD5000AAKX 16MB 3.5" - im just typing here cause my gameplay records became corrupted since 2 days. some of them are completly broken, others have huge color issues and look like a weird 240p with low bitrate even if they should be 720p / ~40mb Rate. 

In games it feels like this harddrive is not able to load the files correctly or completly my system always freezes for short durations and the harddrive is just 2 years and 3 months old.

those stuttering did appear about 1 year ago and im not sure what was causing this untill i saw those corrupted files today in my gameplays.

so ive tried to find any firmware update but theres none… thats the first time a WD HDD dies before reaching 6+ years. also my windows folder on the desk seem to flicker aswell and sometimes the browser just hangs up for some seconds thats weird…

I have this same problem with a BRAN NEW WD Black2 that i got on Feb. 20,2015. So it’s an out of box problem. It seems like the HDD part of the drive is studdering when playing media but not when playing games (Dirt 3). I have also nodiced that my HDD active light becomes steady ON when the studdering occurs.