what's the limit to current hard drive technology

[ucjffj]

based on number of platters and density, can people predict what a theoretical capacity limit would be in the future?

 

[Matthias99]

I don't understand your question. While there are theoretical limits on storage density for magnetic platters (beyond a certain minimum size, the magnetic fields just don't hold stably), this does not imply any sort of *capacity* limit for a hard drive. You can always add more/bigger platters of the same density, although the drive will run slower and/or consume more power and/or be physically larger. Plus, with technologies like RAID, you can create virtual drives made up of multiple physical disks.

 

[Cogman]

I believe I read once that with no future advancements other then sensitivity, the limit to HD size was about 3 tera bytes. or some rediculously high number like that. (terrabyte = 1000 gb).

 

[ucjffj]

Originally posted by: Matthias99
I don't understand your question. While there are theoretical limits on storage density for magnetic platters (beyond a certain minimum size, the magnetic fields just don't hold stably), this does not imply any sort of *capacity* limit for a hard drive. You can always add more/bigger platters of the same density, although the drive will run slower and/or consume more power and/or be physically larger. Plus, with technologies like RAID, you can create virtual drives made up of multiple physical disks.

i'm asking the capacity limit of 1 physical 3.5" hard disk

 

[Sahakiel]

Originally posted by: ucjffj

Originally posted by: Matthias99
I don't understand your question. While there are theoretical limits on storage density for magnetic platters (beyond a certain minimum size, the magnetic fields just don't hold stably), this does not imply any sort of *capacity* limit for a hard drive. You can always add more/bigger platters of the same density, although the drive will run slower and/or consume more power and/or be physically larger. Plus, with technologies like RAID, you can create virtual drives made up of multiple physical disks.

i'm asking the capacity limit of 1 physical 3.5" hard disk

Half-height or full? 1 platter or 12? How many RPM? Magnetic, megneto-optical, optical, or electrical? Number and type of fail-safes. Single sided, double sided, or multiple layer (if applicable)?
Please clarify the specifications of your arithmetic equation.

 

[ucjffj]

Originally posted by: Sahakiel

Originally posted by: ucjffj

Originally posted by: Matthias99
I don't understand your question. While there are theoretical limits on storage density for magnetic platters (beyond a certain minimum size, the magnetic fields just don't hold stably), this does not imply any sort of *capacity* limit for a hard drive. You can always add more/bigger platters of the same density, although the drive will run slower and/or consume more power and/or be physically larger. Plus, with technologies like RAID, you can create virtual drives made up of multiple physical disks.

i'm asking the capacity limit of 1 physical 3.5" hard disk

Half-height or full? 1 platter or 12? How many RPM? Magnetic, megneto-optical, optical, or electrical? Number and type of fail-safes. Single sided, double sided, or multiple layer (if applicable)?
Please clarify the specifications of your arithmetic equation.

hmm, getting tricky. i'm just thinking current type of desktop hard drive, can the limit be predicted. similar to people saying cpu's will reach limit in few years since they can only shrink so much

Half-height or full?

they have different height 3.5" hdd?

1 platter or 12?

whatever is physically possible. 100 if they can do it

How many RPM?

that affects capacity?

Number and type of fail-safes.

i have no idea. whatever is current standard i suppose...

Single sided, double sided, or multiple layer (if applicable)?

whatever's physically possible in consumer desktop hard drive



you guys really are highly technical

 

[klaviernista]

Based on the way you asked your question then theoretically there is no limit to storage density for a hard drive based on current magnetic technology or even technology years ago. Technically you could just keep adding platters and heads infinitely and have one huge multiplatter hard drive. No one does this however because of cost and reliability issues. More platters and heads equal more stuff spinning around like crazy in a confined space eqauls a greater chane of disk failure (all it takes is for one of those heads to crash and your entire drive is shot).

Storage density for most harddrives isn;t reported in the manner I cited above (i.e. total storage capacity). Rather, its refered to in units of Gigabits per square inch (US) or Gigabits per sqaure cm (metric). Current/near future magnetic thin film technology (which is what is used in irtually all consumer hard drives) is pushing ~100-130 GB/square inch. Thats per magnetic layer. It is possible to have multiple recording layers even in straight up pure magnetic media (though you typically see multple recording layers in mageto-optical media). You can do the math for yourself to figure out what a storage density of 100-130 GB/square inch translates comes out to be on a single layer, single 3.5 diameter platter disk.

As for theoretical density, thats a touhg question. I work at the U.S. Patent Office and examine recoridng media applications, so I see stuff all the time and just about everyone is working towards expanding storage density. The big hype in this area is/has been the development of nanodot media (someone posted an article about this a little while back on this forum that I posted a detailed response to, so just search for my response to that thread if you are interested). but sufficie it to say that nano-dot media are predicted as having storage density well in excess of 1 terabyte/square inch. Thats 1 terabyte storage on a substrate the size of a postage stamp.

So, as yet, I don;t think that the "theroetical limit" of storage density can really be predicted. Technology is evolving very very fast in this area.

 

[klaviernista]

Here is the link to my earlier post about nanodot media.

Nickel Nanodot Harddrives

 

[TheStigma]

I am not aware of any limitation in harddrive capacity we will be reaching in the near future. The main reason we arent seeing even bigger drives allready is mainly because of production costs using new the cutting edge tech is too high to get good sales. We are all the time seeing steady increases in capacity, and i don't forsee any trouble at all reaching up to atleast 1-2TB harddrives or even more.

of course I could be wrong...

On the other hand, the phsical limitaions of the current base-design of harddrives severely limits the read/write speed we are able to achieve. This is simply because the HD relies heavily of physical movement relative between the reader heads and the discs. Theres only so fast you can spin the discs before it becomes unreasonably prone to failures, not to mention lots of heat and noise producion.

My bet is that the base design of storage units will change completely before we really start to feel the limitations of currenty physical limitations, atleast as far as storage-capacity goes. We should have quite a ways to go on disc density yet, but wether or not it will be feasible to produce market-viable HD's using these extreme densities I cannot say.

-Stigma

 

[DrPizza]

On another note, I wonder if market forces will limit the availability or desire to raise the capacities. The big question would be: "what for?" - sure, there are plenty of reasons for *some* people to have large hard drive capacities. But (and I'm beginning to sound like the people who thought 400MB was big enough 10 years ago), very few "normal" people that I know ever come close to using up half of a 40GB hard drive. Sure, I've got 360GB on my computer, and much of it is used, but I'm not the average user. And, for me, the multiple hard drive solution was pretty simple.

 

[klaviernista]

Originally posted by: DrPizza
On another note, I wonder if market forces will limit the availability or desire to raise the capacities. The big question would be: "what for?" .

Server storage for one. (2 huge capacity drives in Raid 1 might be more cost efficient then the 20 or so in a current server rack.

DVD audio for two

Next generation games for three (average install now is ~6 GB, 5 years from now it might be double or triple that

And of course, not to forget teenagers, next generation virtual holographic porn takes up a lot of space LOL

 

[klaviernista]

also, I recently saw a 600GB commercial HD for sale, so the terabyte drive is not terribly far off.

 

[tart666]

at SPIE 2003 microlithography conference there was a nice overview talk about lithography problems encountered by the magnetic storage industry. In particular, their Critical Dimension (CD) is the read head track width, is scaling far more rapidly than the gate length (0.13um, 90nm, 65nm, etc) in semiconductor devices. By year 2010 the capability of best steppers will not satisfy the hard drive's industry requirements, i believe he proclaimed. At that time, the rate of density increase will be equal to the rate of gate length progress, or new storage technology will have to be developed.

 

[crumply]

the most recent scientific american had a good article about the theoretical limits of current computer technology, and the future use of optical computing, but i cant remember if the article dealt with your specific question.