Cost of DVD as data storage versus HDD (UK)

guv wrote:
On Fri, 29 Oct 2004 00:05:25 +0100, Tim Auton
wrote:
"Simon Finnigan" wrote:
half_pint wrote:
[snip]
Few failures initially, reaching a maximum and then falling back to
zero once all have failed.

No its bath shaped you troll.

Ahhhh, I`d presume from your statement that you consider yourself more
qualified than me in the field of statistics. Please cite your
qualifications, and name the type of statistics used to describe the
lifetimes of components. No hints from anyoen else please, lets see if
half_wit has any clue at all about this.

You're an idiot if you think qualifications in statistics qualify you
to define the failure curve of electro-mechanical devices (apparently
without data or any understanding of engineering). Odds-on
electro-mechanical devices will fail within the first few months
(manufacturing defects) or after a relatively long period of time (a
few years, when stuff wears out). In simple terms, if it lasts six
months there is a very good chance it will last three years.

Not that your reply was in my direction - but the orignial point was
the belief this continually used 3gig drive would last 100 years.

Using stats or mechanics as your argument, the chances of that
happening are Zero. Or do you suggest otherwise?

That I can't argue with. I believe I've been corrected on the meaning
of MTBF on this group before.

Do you expect me to read the whole thread? I thought I was doing
rather well going back and reading a couple of posts ;o)

My apologies to all (especially the "idiot") if the comments I made
were out of context, but in the immediate context I stand by my
position. It's a bathtub curve. I guess the rest of you are talking
about the second peak (which probably does have a form adequately
described by some common statistical method) and yes, beyond the
second peak of the bathtub curve there is a fall to zero as the number
of functional units approaches zero. There is a finite lifetime which
doesn't have a mean of 100 years.


Tim
--
Anyone who qualifies their comments with "just my
two cents" is usually over-valuing their contribution.

"Simon Finnigan" wrote:
[snippage]
Perhaps if you want an intelligent conversation, you should avoid the
insults. It doesn`t make you look clever you know, certainly when you don`t
give a well considered, intelligent rebuttal to the arguement that`s upset
you so much.

Note to self #1: Read entire thread before posting.

Note to self #2: Don't post drunk.

Note to self #3: Remember #2.


Tim
--
Anyone who qualifies their comments with "just my
two cents" is usually over-valuing their contribution.

"half_pint" wrote:
[snip]

I think he 'over trolled' himself there, such blatently obvious trolling
will earn
him no stars on the trolls hall of fame.

Note to self #1: Read entire thread before posting.

Note to self #2: Don't post drunk.

Note to self #3: Remember #2.


Tim
--
Anyone who qualifies their comments with "just my
two cents" is usually over-valuing their contribution.

"guv" wrote in message
...
On Thu, 28 Oct 2004 20:19:46 +0100, "half_pint"
wrote:

It definately would write and read faster than your current 3 gig
drive. The motherboard in a new system, would also ensure faster
access times and faster throughput.

However such factors are not relevant as the drive speeds are
basically the same
and I would imagine electronic factors, bus speeds, are much faster
than mechanical ones such as data transfer rates to a hard drive.

You`re kidding right? How fast does your drive read/write data? A
quick
check on nero shows that each of my drives hits 40 megs a second, and
I`d
be
surprised if your 7 year old drive can hit 10 megs a second.
Technology
has
moved on a huge way since you bought your drive!

Your drive spins at either 5400 or 7200, the *same* as mine.

As has already been said *your* drive does *not* spin at 7200rpm.

Not what I said "Your drive spins at either 5400 or 7200, the *same* as
mine"

Miine spins at 5400 (5401 I think), which statisfies the the 5400 or 7200
clause.



Why not offer the info on the drive make and model, and we can
demonstrate with hard facts your assumptions on speed of throughput,
read and write are incorrect.

I would wager that even 4000rpm laptop drives far out perform your 7
year old 3 gig drive.

When I first started playing with analogue Video capture about 6 years
ago, only SCSI drives were capable of substained write capabilities
needed of about 7Mbps. Now, *every* IDE drive on the market can
*easily* cope with that and pass the figure needed probabily in excess
of 8 times what is needed.

Something that should be pretty obvious, the fact that technology
continues to improve in leaps and bounds. Something, everyone readily
accepts as a fact and easily provable with stats on the net. I can
only assume you are playing games if you cant see this to be the case
and are acting as a troll.


However what you fail to realise is that data just behind the read head
requires one revolution for it to be read (unless it has multipule read
heads).
So my 5400 is only about 33% slower than a 'modern' 7200 drive.

A fact which even the most persistant of trolls cannot deny.






--
www.senaction.com

"guv" wrote in message
...
On Fri, 29 Oct 2004 00:05:25 +0100, Tim Auton
wrote:

"Simon Finnigan" wrote:
half_pint wrote:
[snip]
Few failures initially, reaching a maximum and then falling back to
zero once all have failed.

No its bath shaped you troll.

Ahhhh, I`d presume from your statement that you consider yourself more
qualified than me in the field of statistics. Please cite your
qualifications, and name the type of statistics used to describe the
lifetimes of components. No hints from anyoen else please, lets see if
half_wit has any clue at all about this.

You're an idiot if you think qualifications in statistics qualify you
to define the failure curve of electro-mechanical devices (apparently
without data or any understanding of engineering). Odds-on
electro-mechanical devices will fail within the first few months
(manufacturing defects) or after a relatively long period of time (a
few years, when stuff wears out). In simple terms, if it lasts six
months there is a very good chance it will last three years.

Not that your reply was in my direction - but the orignial point was
the belief this continually used 3gig drive would last 100 years.

Using stats or mechanics as your argument, the chances of that
happening are Zero. Or do you suggest otherwise?

Well its irrelevant anyway, as the drive will and indeed has "lasted
forever"
forever being "as long as I wanted it to" 2 and 3 gig drives are virtually
worthless these days, try buying one on Ebay, you will spent more on the
postage than you will on the drive, a bit like the 4 16meg simms I pulled
from
my machine, I cant be arsed to sell them because the £1 or £2 I would get
is just not worth the effort, it would involve a hour or so of effort and I
don't
work for below the minimum wage.



--
www.senaction.com

"Simon Finnigan" wrote in message
...
[snip]
Ok, so my drive spins at 7200 rpm, the same as yours. How big are your
platters? Lets be VERY generous, and say the full 5 gig capacity of your
drive is on a single platter. My smallest drive is 180 gigs - lets say
there are 3 platters there. My platters therefore hold 60 gigs each,
despite being the same physical size as your platters. Therefore the
data density on my platters is 12 times greater than on yours.

Therefore, for each revolution of the platter, my drive can read 12 times
more data. That`s 12 times the amount of data in the same amount of
time, making the data transfer rate 12 times greater.

Unless I'm mistaken, you're right about the relative data density (assuming
one platter for the 5GB drive), but that number is the product of two
others: relative bits per unit length (along the track), and a factor you
ignored, relative tracks per unit length (radially). The latter affects
capacity, while the former (along with spindle speed) affects transfer rate.

Alex

I have never heard about it either, but I usually search before posting. I
heard about Weibull distribution before, so here is the result:
http://www.weibull.com/hotwire/issue21/hottopics21.htm

Interestingly enough very small times and very long times are not plotted. I
guess you can figure out the reasons.

"Simon Finnigan" wrote in message
...
wrote:
On Thu, 28 Oct 2004 20:44:32 +0100, "Simon Finnigan"
wrote:

half_pint wrote:

Few failures initially, reaching a maximum and then falling back to
zero once all have failed.

No its bath shaped you troll.

Ahhhh, I`d presume from your statement that you consider yourself
more qualified than me in the field of statistics. Please cite your
qualifications, and name the type of statistics used to describe the
lifetimes of components. No hints from anyoen else please, lets see
if half_wit has any clue at all about this.


I've no qualifications in statistics at all but I, along with
thousands of other students of electronics, had the words 'bathtub
curve' drilled into me all the way through college.

I`ve NEVER heard of it being described as a bathtub shape. How long ago
was
your education, out of interest? What type of statistics would you use to
describe the failure rates? Everytime I`ve ever seen the relevant type of
stats being used, it`s always been a bell shape. Adjusting the parameters
could just about come up with a very weird bath-tub shape, but it`s
certainly nothing like a bath-tub as I know it :-) Pretty much all the
time
I`ve ever seen it used, it`s given a nice bell shape. Sometimes short and
fat, sometimes tall and thin, but always a recognisable bell. ~66%
withing
1SD of the average failure time, ~66% of the remained between 1 and 2 SD
of
the average and so on. This inevitably leads to a nice bell shape -
exponential decay and all that.

--
What am I selling on ebay right now?
http://tinyurl.com/38yjc
Earn money reading emails!
http://tinyurl.com/2pcgm

half_pint wrote:


"guv" wrote in message
...
On Thu, 28 Oct 2004 20:19:46 +0100, "half_pint"
wrote:

It definately would write and read faster than your current 3 gig
drive. The motherboard in a new system, would also ensure faster
access times and faster throughput.

However such factors are not relevant as the drive speeds are
basically the same
and I would imagine electronic factors, bus speeds, are much faster
than mechanical ones such as data transfer rates to a hard drive.

You`re kidding right? How fast does your drive read/write data? A
quick
check on nero shows that each of my drives hits 40 megs a second, and
I`d
be
surprised if your 7 year old drive can hit 10 megs a second.
Technology
has
moved on a huge way since you bought your drive!

Your drive spins at either 5400 or 7200, the *same* as mine.

As has already been said *your* drive does *not* spin at 7200rpm.

Not what I said "Your drive spins at either 5400 or 7200, the *same* as
mine"

Miine spins at 5400 (5401 I think), which statisfies the the 5400 or 7200
clause.



Why not offer the info on the drive make and model, and we can
demonstrate with hard facts your assumptions on speed of throughput,
read and write are incorrect.

I would wager that even 4000rpm laptop drives far out perform your 7
year old 3 gig drive.

When I first started playing with analogue Video capture about 6 years
ago, only SCSI drives were capable of substained write capabilities
needed of about 7Mbps. Now, *every* IDE drive on the market can
*easily* cope with that and pass the figure needed probabily in excess
of 8 times what is needed.

Something that should be pretty obvious, the fact that technology
continues to improve in leaps and bounds. Something, everyone readily
accepts as a fact and easily provable with stats on the net. I can
only assume you are playing games if you cant see this to be the case
and are acting as a troll.


However what you fail to realise is that data just behind the read head
requires one revolution for it to be read (unless it has multipule read
heads).

That's called "latency", and it's only one factor in drive performance.

So my 5400 is only about 33% slower than a 'modern' 7200 drive.

A fact which even the most persistant of trolls cannot deny.






--
www.senaction.com

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

Simon Finnigan wrote:

wrote:
On Thu, 28 Oct 2004 20:44:32 +0100, "Simon Finnigan"
wrote:

half_pint wrote:

Few failures initially, reaching a maximum and then falling back to
zero once all have failed.

No its bath shaped you troll.

Ahhhh, I`d presume from your statement that you consider yourself
more qualified than me in the field of statistics. Please cite your
qualifications, and name the type of statistics used to describe the
lifetimes of components. No hints from anyoen else please, lets see
if half_wit has any clue at all about this.


I've no qualifications in statistics at all but I, along with
thousands of other students of electronics, had the words 'bathtub
curve' drilled into me all the way through college.

I`ve NEVER heard of it being described as a bathtub shape. How long ago
was
your education, out of interest? What type of statistics would you use to
describe the failure rates? Everytime I`ve ever seen the relevant type of
stats being used, it`s always been a bell shape.

The bell curve is called the "normal distribution" of data about a mean.
Failures in electronics exhibit something more akin to a skewed bimodal
distribution, with a peak early, a peak late, and a fairly wide separation
between them, which does if you look at it the right way kind of resemble a
bathtub.

Adjusting the parameters
could just about come up with a very weird bath-tub shape, but it`s
certainly nothing like a bath-tub as I know it :-) Pretty much all the
time
I`ve ever seen it used, it`s given a nice bell shape. Sometimes short and
fat, sometimes tall and thin, but always a recognisable bell. ~66%
withing 1SD of the average failure time, ~66% of the remained between 1
and 2 SD of
the average and so on. This inevitably leads to a nice bell shape -
exponential decay and all that.

Well, you might have seen that in a statistics class, but statistics classes
deal in methods of calculation, not in actual performance of real-world
devices. If you're referring to the published MTBF numbers, they're not
based on service life but on probability of failure _during_ the service
life, which is why the numbers are so large, with the assumption being that
the device will be replaced due to obsolescence long before wear becomes an
issue. Their purpose is to allow an organization to estimate maintenance
requirements and maintain adequate quantities of spares when they have a
large number of devices of like kind in service.


--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

"Tim Auton" wrote in message
...
"half_pint" wrote:
[snip]

I think he 'over trolled' himself there, such blatently obvious trolling
will earn
him no stars on the trolls hall of fame.

Note to self #1: Read entire thread before posting.

Note to self #2: Don't post drunk.

Note to self #3: Remember #2.


I was refering to Simon Finnigan of course, not you, if that is any help.



Tim
--
Anyone who qualifies their comments with "just my
two cents" is usually over-valuing their contribution.