I only real deal with file system type recovery but I have a quick question for you physical recovery experts.

Basic question is what can cause the drive to read at a normal 80MB/s, but only write at 12-16MB/s.

SMART has an abnormal reallocation sector count, MHDD reports about 60 green, but otherwise completes a SCAN normally. What kind of things are the cause of normal read speeds and slow writes? Is it media? heads/amp? Firmware/SA damage?

I've never had much interest in the physical side of things before but I must have read about 6 hours yesterday through the forum, ATA spec, terminal use, the little I could find on vendor specific commands. All quite facinating actually, but I just couldn't get a firm grip on what could cause this problem.

Thanks guys.

These truthfully seem to be the "drives of the hour" so to speak. It seems that we all are seeing these in. I would initially say that given the age of these drives and the amount of failures in comparison to normal drives that either the firmware in these have serious bugs or they were really built with crappy material and are suffering errors more than usual for WD due to crappy parts.

Degraded media or head damage could be one cause. The other could be you have components heating up and this is only a symptom for an upcoming total failure. If SMART is showing abnormal reallocation of sectors or really high then I'd assume that you have a physical problem with heads or media but there isn't a lot of info to go off of.

What about the tons of 5000 running smoothly since 2006 ? Firmware doesn't seem to have flaws, it's the users that MISUSE drives.

Thanks for the reply I appreciate it since I am sure it's a relatively simple sounding question, and the fact I don't have alot of information to provide as I am not into the physical repair nor do I have advanced tools.

I did forget some information. It came to me as a USB backup enclosure with data loss. 2 of these drives in JBOD, the drives are recerts which is another factor. I recovered the data, and the customer bought a new backup solution. So this drive is destined to be destoryed anyway. I have no idea how roughly the encolsure was handled, but that usually seems to be the issue.

I am not an expert in the slightest with physical disk work, but I have dealt with 100's of drives and never saw a hard drive pass all "simple" checks(with the exception of SMART high reallocation) yet write at such a slow rate.

I don't want to save the drive, data is recovered and drive blanked but all of a sudden became interested in this error. Any information I can provide with freeware tools that I am not providing? I understand this isnt a very interesting topic to experts but just trying to expand my knowledge. In the end it doesn't matter as I will just throw away the drive anyway but if I have a chance to learn something I am all for it.

Thanks again!

Name another drive that you've seen so many of in a 2 year span that didn't have a known factory condition? Definitely could be from user misuse because any drives that are included in externals that are built from 3.5" instead of 2.5" run into more issues and I actually stated previously that I thought he had a head or media error. Any suggestions Black on his question?

@aicjofs - still sounds like a head or media error like I said in my first post. Reading is easier than writing for heads. I can't go any further than that but it def sounds like you have a head or media problem.

I understand this, hence why write performance is always worse on healthy drives.



Of course it would be a generalization but do find any correlation with number of head and platters and the write performance suffered?

I.e. if this is a 3 166GB platter, 6 head drive. If write performance is say 1/4 of what it normally should be can you say it's more likely a head issue? Any thing like that or is that just not the case often enough at all to even try to generalize?

It's ok if you can't go further... like I said before 6 hours of reading and between the secrecy, the general lack of info, and how that information is so decentralized, I am happy with what I have learned so far, and content just to get a reply!

Additionally I would point out that the WD5000KS are the ones that everyone is seeing tons of and not the AAKS.

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You don't have to backup all of your files, just the ones you want to keep.

Unfortunately there was no 'internet option' for me to expand my knowledge: only hard work, investment on myself and gear and getting educated/trained. You can get some generic info off the net, but if you want something more you have no choice. Why people don't want to admit that many things are not for everyone?

Sorry to hear that you had no internet option, must have been really hard for you back then. Today you are probably thrilled for a forum like hhdguru where people share information about things to help others? Would have probably been a big help for you back then, you probably are better for learning the hard way though they say. So you never bothered to say in your posts what you thought of the issue with the drive. What do you think?

The trouble is that I know exactly what the problem is, I have the solutions, I have built my own tools either hw and sw. But there's a world of difference between things to say and jobs to do, and I 'need' cash to live. Moreover, I openly protect market persistence and professionality. Anyway, even if I teach you everything and after years you are able to build my tools, you still are not BlackST and this makes the difference - replace my name with a random pro at your choice. Many people tried, the results were 'dr equipment for sale...'