"Arny Krueger" wrote in message ...
"ScottW" wrote in message
news:4uR3c.4528$Nj.1455@fed1read01
"Arny Krueger" wrote in message
...
"Powell" wrote in message

"Robert Morein" wrote

Morien still hasn't substantiated this claim by any means
other than personal attack and introduction of a discussion
of hard drives and CPU fans, not facts about CD burners.

There is a naive misconception as to what MTBF means.

True, but Morein so far you haven't made the issue
relevant here.

It's a good thing businesses are run-out of the front
office and not out of engineering. Your quoted
statistical models have little practical value in the
real world. Hard drives are spec build based on
managerial accounting (cost/profit). As one Western
Digital representative put it, our drives have a ½ of
1% failure rate. There is no economic advantage in
producing higher quality in a highly competitive
marketplace. So you can lump-in all your stats and
it still comes out the same number (½ of 1% failure
rate).

That would be ½ of 1% per what time period?

IME it might be ½ of 1% per month, or something like that.

Its a quality number, DOAs. Drives that fail the initial format
attempt.

Oh, ½ of 1% AQL.

NO, the term AQL is usually used to refer to sample plans that have a
90% probablity of accepting lots of product with a given percent
defective.
They don't provide much info on the actual percent defective or how
many defectives are required before the plan will give a decent
probability of rejecting the lot.
They are (as one of my ASQC course instructors once said) a license
to ship ****.
LTPD (Lot Tolerant Percent defective) plans give the inverse or a
90% probability of rejecting a lot of given percent defective.

One is biased to protect the customer from getting lots of bad
product, the AQL is biased toward protecting the supplier from
rejecting lots of acceptable quality products. Apparently WD has an
AQL mentality.

BTW, I just plucked this quote off an internal e-mail group at work.
You might want to send it off to the moron rep at western digital:

"I too used to favor Western Digital drives (ever since about the
420MB
versions many years ago.)

More recently (past year or so) the WD drives I've been using have
been
failing more rapidly. I do RMA my drives but only when I can
successfully run a CIA-grade wipe utility off a linux boot floppy on
it
(lately, I've been able to do this despite problems on the drive cause
they haven't been full crashes)

I'm seeing my WD drives now fail at least twice as frequently as they
used to...I only buy them when they're free or close to it. Seagates
seem to be the next drives I'll be buying in mass "


ScottW