WD Caviar RE "high reliability" drives

C

chrisv

What's the scoop on these? They cost a bit more than regular WD
drives, but have the fluid bearings and claims of higher reliability.
 
I

Iago

chrisv said:
What's the scoop on these? They cost a bit more than regular WD
drives, but have the fluid bearings and claims of higher reliability.

I don't remember a claim of high reliability, but that can be just
semantics. Those drives should work better with a RAID controller.

Seagate came up with a similar line of drives and both vendors agree
that there are benefits only in RAID configurations
 
L

larry moe 'n curly

chrisv said:
What's the scoop on these? They cost a bit more than regular WD
drives, but have the fluid bearings and claims of higher reliability.

I'd like to know why MTBF ratings keep going up, now over a million
hours for some drives, but the expected lifespan remains at five years
(and that may be for only eight hours of use per day). Because if
drives really are better now, shouldn't their expected lifespans also
be higher?

I thought that all new WD drives now use fluid bearings. I know that
the 120GB one I bought this Labor Day does.
 
R

Rod Speed

larry moe 'n curly said:
chrisv wrote
I'd like to know why MTBF ratings keep going up, now over a million
hours for some drives, but the expected lifespan remains at five years

That isnt the expected lifespan, that's the design life, a different animal
entirely.
(and that may be for only eight hours of use per day).
Because if drives really are better now, shouldn't their
expected lifespans also be higher?

That 5 years aint the expected lifespan.
I thought that all new WD drives now use fluid bearings.
I know that the 120GB one I bought this Labor Day does.

Yep.
 
N

news.telenet.be

Folkert Rienstra said:
Corse he will, doesn't he always?

I was a WD fan, but I've just had my third WD Caviar drive (out of a sample
of 4) fail. The failed drives lasted about 12-18 months. The survivor is
just under three years old. They weren't overheated - Two were used in a PC
fitted with tripple drive fans and one in a big all metal fan equipped 5.25"
external enclosure that was never transported/moved. All three made strange
mechanical noises - typically at startup - anything from a quiet ticking to
a screech. I've decided to replace the latest failure with a Samsung
Spinpoint drive. I've no idea if they are any better - will let you know how
they do in three years time.
 
P

Peter

I was a WD fan, but I've just had my third WD Caviar drive (out of a
sample
of 4) fail. The failed drives lasted about 12-18 months. The survivor is
just under three years old. They weren't overheated - Two were used in a PC
fitted with tripple drive fans and one in a big all metal fan equipped 5.25"
external enclosure that was never transported/moved. All three made strange
mechanical noises - typically at startup - anything from a quiet ticking to
a screech. I've decided to replace the latest failure with a Samsung
Spinpoint drive. I've no idea if they are any better - will let you know how
they do in three years time.

That is why you should have a reliable backup. Any brand hard disk can fail.
Any time.
With reliable backup it is just a nuisance to restore systems after
replacing failed hard disks. You have a bit less of that hassle if your
disks are better quality, thats all. You pay for it.
 
A

Arno Wagner

That is why you should have a reliable backup. Any brand hard disk
can fail. Any time. With reliable backup it is just a nuisance to
restore systems after replacing failed hard disks. You have a bit
less of that hassle if your disks are better quality, thats all. You
pay for it.

Actually for disk failures RAID1 or RAID5 (with not too many disks)
is fine. Backup is more needed for other sources of destruction like
system failure (think fire, theft, flooding,...) or user and
software error. Repairing a disk in a RAID array (other than RAID0
obviously) is usually quite painless and takes little time.

Arno
 
C

chrisv

Rod said:
Just PR bullshit.


That's really just the cost of the longer warranty.

Hmm... It takes the warrantee from 3 years to 5... I wouldn't want
to pay anything for that.
They all do now.

Odd. They do say that their cheap "mainstream" line uses the fluid
bearings

http://www.westerndigital.com/en/products/Products.asp?DriveID=41

But there's no mention of it on the "high performance" EIDE line

http://www.westerndigital.com/en/products/Products.asp?DriveID=117&Language=en
 
A

Arno Wagner

Previously larry moe 'n curly said:
chrisv wrote:
I'd like to know why MTBF ratings keep going up, now over a million
hours for some drives, but the expected lifespan remains at five years
(and that may be for only eight hours of use per day). Because if
drives really are better now, shouldn't their expected lifespans also
be higher?

No. The "component life" is the time the MTBF is valid. The MTBF
is not a lifetime bat a failure probability:

1 / <MTBF> = <propapility of failure per hour of operation>

It is valid as long as the device is younger than the "lifetime".
After that the device enters a "wear out" period where the
failure rate per hour increases. Actually a new device also
has higher failure rate, ofteh called "infant mortality", but
this is usually not shown today. It can usually be avoided by
doing a "burn in", e.g. a week of running hot (accelerates ageing)
under full load.

Since the components of the drive age, the MTBF eventually rises.
Complex epelctronics usuelly have 5 years lifetime, mostly because of
electrolyte capacitors that do not live too long but are far cheaper
than, e.g., long-loved ceramics. Semicondictors run cold (e.g. 40C)
have something like 30 years lifetime. It halves every 10C or so,
regardless of whether the device is operating or not. The base
temperature may be significantly different for power semiconductors
(also current PC CPUs). For mechanics it depends. They are usually
manufactured just well enough that they do not bring the system
lifetime down.
I thought that all new WD drives now use fluid bearings. I know that
the 120GB one I bought this Labor Day does.

The bearings are not the only thing that fails.

Arno
 
G

Guest

Arno said:
Complex epelctronics usuelly have 5 years lifetime, mostly because of
electrolyte capacitors that do not live too long but are far cheaper
than, e.g., long-loved ceramics. Semicondictors run cold (e.g. 40C)
have something like 30 years lifetime. It halves every 10C or so,
regardless of whether the device is operating or not.

30 years for a semiconductor at 40C is unbelievably low and is closer
to the expected lifespan of an electrolytic capacitor. Any semi that
cool should last more like 100-300 years, but motor and head positioner
chips often run at 70-90C.
 

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