Warranty on Hard Drive

John Esposito
John Esposito used Ask the Experts™
Does the Western Digital Ultrastar 14TB DC HC530 7200 RPM SATA 6.0Gb/s 3.5" Data Center Internal Hard Drive - 0F31284 come with a 5-year warranty or a 2 year warranty? On the website it says Up to 2.5M hours MTBF with a 5-year limited warranty but under the warranty and returns Limited Warranty period parts and labor 2 years.

Western Digital Ultrastar 14TB DC HC530 7200 RPM SATA 6.0Gb/s 3.5" Data Center Internal Hard Drive - 0F31284

Not quite sure what the difference between mean
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
David FavorFractional CTO
Distinguished Expert 2018
"Up to 2.5M hours MTBF with a 5-year limited warranty" means...

If you drive dies in < 5 years + < 2.5M hours then terms of warranty are valid.

Anything over, warranty is invalid.
Most Valuable Expert 2013
Good luck finding 2.5M Hours in a 5 year period (43,830 hours) :)

With the HC530 you simply have WDs standard Limited Warranty for 5 years - however with all WD drives this is from the date WD supply their authorized distributor - it may not be 5 years from your purchase.


The two year Warranty you're looking at is NewEgg's - as their customer they will cover your drive for the first two years under the same terms but you can equally go back to WD for replacment (which is all NewEgg will do) it's just added value from the retailer for you.
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013
You assume you have the ability to time travel.  24 hours in a day x 365 days a year = 8760 hours in one year.  43800 in 5 years.  No where near 2500000 hours.  2.5M hours would be 285+ years.

You should read up on MTBF:

And any question regarding warranty validity should be directed to the manufacturer - just because someone tells you on a forum what they think the warranty is/means doesn't mean the manufacturer will honor it.


So I am looking at a 2 year limited warranty if it dies?
Most Valuable Expert 2013
No, you get a five year warranty, the first two of which are covered by both NewEgg AND WD.
John TsioumprisSoftware & Systems Engineer
IMHO don't invest on a single huge disk ..better to buy 2 8Tbs drives, unless you need the maximum of space, do remember that any HDD doesn't cover your data..at best you get a new drive, but in case of failure the real asset - the data - is gone.
Top Expert 2014
Pity they run concurrently, 2+5 years would be a bonus.
I was going to say beware shingled drives but that one isn't, some 14TB ones are but not the HC530.
John TsioumprisSoftware & Systems Engineer
small correction to my above post : " any HDD" i was meaning " any HDD warranty"
LOL, MTBF is a statistical failure rate. A 2.5 million MTBF does not require that the drive run for 2.5 million hours, any more than a car travelling at 100Mph has to travel 100miles. It also does not imply that a drive will last that long.

A 25 year old human has an MTBF of something like 900 years!
Thank you for the link about MTBF.  It clarifies what has bothered me for decades.  It also implies to me that MTBF has minimal value.

Let me give an example.  I manufacture a part that works properly for about 1,000 hours and then generally fails.  I test 1,000 of the parts for 900 hours and none fail.  MTBF=(1,000x900)/0 (units tested * hours tested/number of failures).  My MTBF is +infinity.

Now, imagine that I test them for 1,100 hours. Based on my initial assumption (generally fail after 1,000 hours), let's assume all fail between 1,000 and 1,100 hours.  The MTBF will be (1,000x1,100)/1,000=1,000 hours.  That seems like a good measure.

What troubles me is that the MTBF is heavily dependent on how long I do my testing.  Shouldn't there be a requirement, for example, that one must test until a significant number of devices fail?

What am I missing here?
CompProbSolv> In your example, the device in question had a variable MTBF, depending on its age. Under 900 hours, MTBF was indeed infinite. (or very high, and you needed to test maybe a million of them to get a more accurate number). As this device ages past 900 hours its MTBF began to rapidly drop.

If all fail between 1000 and 1100 hours, then after 1000 hours, (in a linear manner) they have an MTBF of 50 hours.

A lot of complex, mechanical devices have a variable MTBF. It is usually low early in their life, stable for a while, then starts to increase. Take a car for example. A brand, new car will generally have a LOW MTBF, since any mistakes or weak components will tend to show up then. Typically, dealers will want to reexamine the vehicle for free a month or so after you buy it, and frequently there will be a list of small issues to resolve. (and occasionally major ones). The MTBF will approach a high value after maybe 6 months. From there on the vehicle will be reliable until age catches up with it. Perhaps after 5 years things will start to wear out, and the MTBF will reduce. It will keep reducing from then, as the vehicle gets old, and more bits start to fail due to age. This is termed the "bathtub curve"
Dr. KlahnPrincipal Software Engineer
Side note:  If the concern is maximizing the warranty, then buy the drives with a credit card that extends the manufacturer's warranty.  Most AmEx and many Visa cards double warranties up to one year, and add one additional year for items with warranties over one year.

Mind you, it does no good to have warranty extensions on drives that are going to give trouble.  I only buy WD Enterprise class drives now (red, purple, gold, REn) after an episode with several Seagates earlier this year.  But that's a personal opinion and as many will be on one side of that fence as the other.

" I only buy WD Enterprise class drives now (red, purple, gold, REn) after an episode with several Seagates earlier this year"

Yeah, trouble with that is that once you have identified a range of drives with a high failure rate, they are probably off the market, and new ones are vastly different. Both Seagate and WD have produced a few lines of lemons over the years, as well as a few lines of bulletproof drives. Even within a range that have the same model number, often minor mechanical changes or firmware updates can mean reliability can differ greatly from month to month.
Top Expert 2016
Backblaze publishes disk failure rates https://www.backblaze.com/blog/2018-hard-drive-failure-rates/ In their older records I can confirm that the Seagate 1.5TB drives were a failure waiting to happen.  I have some 750GB drives that are over 15 years old and still spinning.
Top Expert 2013
yep - and i have had bad WD's also….
John TsioumprisSoftware & Systems Engineer
True story of mine about the unreliability of HDDs...
I had an HDD installed on my workstation...it worked fine for a couple weeks and then simply it died
I had it RMA and recieved a brand new..which i toss it in a drawer for a few weeks because in the mean time from getting it back from RMA i had done some work and i wanted to organize it
Installed the brand new RMAed drive...guess what ...DOA
Totally upset i RMAed and i ordered another one (another brand) from another store...
The new drive arrived ...installed ...guess what DOA
I was furious...i phoned the store and practically "ordered" them to prepare me a new HDD that would have been at least connected to a workstation of their own to see it actually working...i drove 100Kms+ recieved the "new drive" exchanging the dead one and went back home...phew it was working...
The drive that came from the other RMA also worked for considerable time till ...with a little help ...i RMAed it again because it was extremely noisy and slow.
This is an example of where I've misunderstood MTBF.  I've assumed it was a characteristic of the product (not an individual, the group of them), not a variable through its life.  If it is variable, how useful is the number when it is new?
Top Expert 2013

imo MTBF is a statistic figure,  to be used only to calculate the overall possibility of failure.
it can be used in extremely secure projects, like moonlandings etc....
for normal, everyday life - it has no use that i know of

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial