How fast are DVD+R drives going to get?

[John]

When I bought a 12x10x24 CD-R/RW drive a few years ago, I hadn't thought
ahead to how fast they would get. Now it seems really slow.

So, I've seen that some 12x DVD+R drives are coming out. I would like a
recordable DVD drive but I can wait if the speeds are going to accelerate
the way CD-R's did. So, does anybody have any idea how fast DVD+R's are
likely to get? Will they get into the 52x range?

 

[Clint]

I'll give you my very un-expert opinion. They might get up to 16x speeds,
but not close to the 52x speeds like CDR drives. The reason I say this is
because

a) The fastest readily available DVD-ROM drives are only 16x, and they've
been out for awhile now. If they could make them faster, they would have
already.
b) 8x DVD+-R is about equivalent to 32-40x CD. The rotational speed and
data transfer rates will limit how much further they can go. At that ratio,
12x DVD is about equal to 48 to 60x CD speeds.

So I'll leave it to the experts now to shoot down my theories...

Clint

 

[Fitz]

Additionally, the recordable media has not kept up with the advances in
recorder speeds. Have you looked for 12X media? Have you seen the price
difference between 2X and 8X media?

I'm using an 8X (R+) / 4X (R-) / 40X CDRW. It's reliable, and more
importantly, it's not particular about what brand or speed media I use- it
works.

Why wait- about the time you feel you've been left way behind, it'll be time
to build a new system anyway. It's like "they" plan it that way- ya think?

Fitz

 

[BarryNL]

I'll give you my very un-expert opinion. They might get up to 16x speeds,
but not close to the 52x speeds like CDR drives. The reason I say this is
because

a) The fastest readily available DVD-ROM drives are only 16x, and they've
been out for awhile now. If they could make them faster, they would have
already.
b) 8x DVD+-R is about equivalent to 32-40x CD. The rotational speed and
data transfer rates will limit how much further they can go. At that ratio,
12x DVD is about equal to 48 to 60x CD speeds.

So I'll leave it to the experts now to shoot down my theories...

As I understand it, the main reason CDs won't get any faster than 52x is
the material strength. If you think back to school physics lessons,
remember centrifugal/centripetal forces - the faster something spins the
greater the forces on it? Basically, much faster than 52x and CDs will
just break up - in fact there's been quite a few cases of CDs
'exploding' at slower speeds than this.

Anyway, apparently DVDs have a lower 1x speed any a higher theoretical
maximum speed so there I think the theoretical maximum for a DVD based
on material strength is likely to be somewhere around 70x - 80x.

This might also be interesting:

http://theage.com.au/articles/2002/12/09/1039379779472.html

 

[BarryNL]

As I understand it, the main reason CDs won't get any faster than 52x is
the material strength. If you think back to school physics lessons,
remember centrifugal/centripetal forces - the faster something spins the
greater the forces on it? Basically, much faster than 52x and CDs will
just break up - in fact there's been quite a few cases of CDs
'exploding' at slower speeds than this.

Anyway, apparently DVDs have a lower 1x speed any a higher theoretical
maximum speed so there I think the theoretical maximum for a DVD based
on material strength is likely to be somewhere around 70x - 80x.

This might also be interesting:

http://theage.com.au/articles/2002/12/09/1039379779472.html

Doh, to correct myself, before anyone else does, this article explains
it better - (looks like 16x will be the maximum):

http://www.pressi.com/int/productnovelty/79202.html

Of course, Blu-Ray type technologies will rewrite the rule book.

 

[Clint]

I think that BluRay may increase how much we can write to a disk, and how
much data can be written, but it won't necessarily increase how fast the
discs can spin. It will probably reset the whole "xx" specification all
over again, much like the CD-R to DVD-+R thing did, as it won't be
comparable to current CD/DVD speeds.

Clint

 

[dg]

There is no such thing as centrifugal force. Centrifugal force was an old
theory that didn't quite pan out. Physics experts now consider it a "non
existant force". Just an interesting piece of info I was reminded of, I
thought I would throw it out here.

--Dan

 

[PWY]

There is no such thing as centrifugal force. Centrifugal force was an old
theory that didn't quite pan out. Physics experts now consider it a "non
existant force". Just an interesting piece of info I was reminded of, I
thought I would throw it out here.

--Dan

I wonder if these experts can explain how an object dropped into a
centrifuge always goes directly to the out side wall and stays there, or how
CDs have been known to explode in fast CD drives ?
I love experts, they're everywhere.

 

[BarryNL]

I wonder if these experts can explain how an object dropped into a
centrifuge always goes directly to the out side wall and stays there, or how
CDs have been known to explode in fast CD drives ?
I love experts, they're everywhere.

It's fairly simple, if you look at any individual point on a spinning CD
it will be travelling in a direction perpendicular to the direction
towards the centre of the CD. Now, following Newton's laws, objects
continue to travel in a straight line at a constant speed unless a force
acts on them, thus something must apply a force towards the centre of
the CD to each particle of the CD to keep it moving in a circular
motion. The "centrifugal force" is actually the momentum of the CD
resisting the change of direction. If this momentum is greater than the
tensile strength of the CD, it explodes - well, breaks up
catastrophically at any rate.

 

[Erez Volach]

I wonder if these experts can explain how an object dropped into a
centrifuge always goes directly to the out side wall and stays there, or how
CDs have been known to explode in fast CD drives ?
I love experts, they're everywhere.

Yeah. Centrifugal force is an imaginary force. Physics "experts" as well as
students can tell you what is the meaning of imaginary force (in a nutshell,
from the viewpoint of an object in circular motion it is the force "acting"
on it outwards of the circle. but this viewpoint is accelerated, ofcourse).
Coriolis force is just as imaginary (and just as practical for application)
force. This latter effect also stems from a rotating (accelerating) system.
What other theory is there other than newton's ?