Disk capacity decreased after LLF (WD6401AALS)

[DerAdler]

Nor does it seem like there is anything wrong with your drive. Benchmarks look normal, size is perfectly normal, SMART data is normal. I think you're just getting worked up over nothing. If your computer is getting slow it's far more likely that the issue is just some crappy software slowing down your system.

Hi data-medics, thank you very much for your reply.
The problem occurred quite suddenly and interested ONLY the partitions on that HD; the system was (and is) working fine.
As described in my first post, even after some disk check (scandisk, virus scan & Co), the problem remained.
I'm quite confident that no crappy software were causing this problem, else all the system would be affected and the problem would occur again after the LLF. Instead, is not.
I had already checked the cable connection, both power and SATA, and physically removed the drive from the PC-case slot and test it on an other PC. Then reconnected it in my PC for the diagnostic tests/benchmarks you see above.
It looks like that the Low Level Format have solved/recovered the disk from its previous "faulty" state. Or maybe the physical removal/reconnection from the motherboard/PSU forced the SATA controller to reset it to the normal speed, according to what arztt said.

I'm using this disk by nearly 5 years and has always worked fine; this is the first time I have issues with it.

Last edited by DerAdler on January 22nd, 2015, 5:40, edited 1 time in total.

[DerAdler]

The drive seems to be 100% OK!

You should check your SATA cable, you have a high 'Ultra DMA CRC Error Count'. Maybe because of this your SATA controller set down the speed to a minimum.

But now this seems to be ok again (nice benchmark). If you have another SATA cable, use it instead of the old one.

Hi arztt, thank you very much for your reply.
As already wrote above, I also verified the cable connections to this HD. Btw, I didn't replaced the SATA cable, though it's working fine now (so I don't think the SATA cable should be blamed).

I also noticed the "Ultra DMS CRC Error Count" in the health status, and I was wondering what may have caused it... probably most of these have been "registered" while the disk was working in oddly/slow way (before the LLF). I'll keep this value monitored, to figure out if it should increase again (or not).

[DerAdler]

You should check your SATA cable, you have a high 'Ultra DMA CRC Error Count'. Maybe because of this your SATA controller set down the speed to a minimum.

But now this seems to be ok again (nice benchmark). If you have another SATA cable, use it instead of the old one.

Another thing the OP could try would be to install the drive's OPT1 jumper. This will reduce the SATA link rate to 1.5Gbps. It could be that a 3Gbps link rate is error prone whereas 1.5Gbps may be error free.

ISTR that some SATA chipsets had problems in this regard. For example, Intel's H67/P67 had a bug that was subject to a recall.

I don't think my SATA chipset have problems with this disk (working to its nominal 3Gbps speed), since it worked flawless for almost 5 years and is working fine now.. dunno what happened, though.
Thank you for your reply, anyway: if the problem should occur again, I'll try your suggestion.

[fzabkar]

The Intel P67 bug manifests itself as a gradual failure over time. It affects the 3Gbps ports but not the 6Gbps.

http://www.anandtech.com/show/4142/inte ... ins-recall

[Anand Lal Shimpi] asked Intel how we’d know if we had a failure on our hands. The symptoms are pretty simple to check for. Intel says you’d see an increase in bit error rates on a SATA link over time. Transfers will retry if there is an error but eventually, if the error rate is high enough, you’ll see reduced performance as the controller spends more time retrying than it does sending actual data.

Ultimately you could see a full disconnect - your SATA drive(s) would not longer be visible at POST or you’d see a drive letter disappear in Windows.

[Dmitri]

Attached below the test screenshots.
Here follows the test logs
HD Tune: WDC WD6401AALS-00L3B2 Health...

What kind of health test you're looking to perform and why you're doing it with HDTune?

If you're concerned about HDD health get HDDScan and run the test there (Surface tests -> Read). It will show you both the detailed speed graph and each of "slow blocks".
To get the distortionless results it would be good to not have other programs running during the test, at least those, which may access the drive.

[DerAdler]

Attached below the test screenshots.
Here follows the test logs
HD Tune: WDC WD6401AALS-00L3B2 Health...

What kind of health test you're looking to perform and why you're doing it with HDTune?

If you're concerned about HDD health get HDDScan and run the test there (Surface tests -> Read). It will show you both the detailed speed graph and each of "slow blocks".
To get the distortionless results it would be good to not have other programs running during the test, at least those, which may access the drive.

Thank you for your suggestion.
Actually I was trying to figure out if any bad blocks/hardware issues were present on my HD.
I tested it first with Western Digital Data LifeGuard Diagnostics, as suggested by WD to open an RMA.

I used HD Tune to perform the Error Scan test; then to get the health information and perform benchmarks, as arztt asked me.

Each of you have his own preferred HD diagnostic software; can't try every program or I'll kill my HD with all these tests. LOL