Next Wave Of Hard Drive Tech: Perpendicular Recording 380
angrytuna writes "New serial technologies are set to replace standard SCSI and ATA (Advanced Technology Attachment) interfaces over the next two years, even as hard-disk drive manufacturers prepare for an entirely new form of bit storage. Perpendicular recording will replace longitudinal recording in storage devices, placing bits on end instead of lying them parallel on the disc surface, thus dramatically increasing the possible storage density."
a shame then (Score:5, Funny)
I wonder which side of the debate the hard-disk manufacturers are on?
Re:a shame then (Score:3, Insightful)
Re:a shame then (Score:5, Informative)
Legitimate content.
It's easy enough to end up with tens of thousands of photographs on your machine if you're in the habit of carrying a digital camera around. Now, think about what happens when you snap video clips the way you currently snap photographs.
This is already happening. With cameras being integrated into phones, it's growing even more.
Re:a shame then (Score:2)
~Berj
Re:a shame then (Score:2)
Data transfer, be it from a hard drive's platter or from a RAM chip, is a fundamentally serial operation. You have an interface of fixed size (number of bus lines, or number of platters with read heads on them), and are modulating in time to transmit data.
While there's a big gap between the two -
Re:a shame then (Score:3, Informative)
Um, I meant *exactly* what I said. I'd like to see access times of new drives be fractions of what they are today, and transfer speeds exponentially, not incrementally, higher.
The point is that "exponentially higher" doesn't mean much if the exponent is very small, or if the duration of a large exponent is very small. That being the case, "exponentially higher" doesn't really mean anything unless you quantify it in terms of rate and time, or at least specify some existing linear growth rate whose coeffi
Windows Longhorn (Score:2)
Backing up LEGAL movies and music
Once again, the corporate market.
Also, if they can be produced cheaper, they'll be used in mail order systems. It's not aways about having the space.
Ben
Re:a shame then (Score:5, Insightful)
Post-editting results in TIFF files that are approximately 10MB in size. All told, this one shoot now occupies over 800MB on my fileserver - from just one hour of shooting.
Oddly enough, people do in fact use vast amounts of storage space for reasons other than sharing mp3s and movies. As technologies improve (cameras increase resolution, video cameras likewise, millions of other reasons), the demand for space will increase as it always has done.
Re:a shame then (Score:3, Interesting)
When you say uncompressed DV resolution... why use a format that isn't even DV if, by all likelihood, you're using something that came off DV? Is it to preserve the 32bpp? Or is this something you rendered yourself?
Excuse the qusetions, just a curious video n00b... I though working with DVs ~215MB/min was bad enough... less than five minutes of footage per gig! Aaargh! High Density resolution is going to murder hard disks!
Re:a shame then (Score:2)
RAID. As soon as I get enough cash to upgrade my system I plan on getting a RAID array so I don't have to worry about one of these drives failing. My old C: drive is like, 6 years old or something crazy like that.
Ahh, now I understand... (Score:5, Funny)
Re:Ahh, now I understand... (Score:2)
Comment removed (Score:5, Funny)
Re:No fair (Score:4, Funny)
Ah, so you didn't get the email telling you how easily you can increase the size of your floppy from 3.5" to 5.25"!
Re:Ahh, now I understand... (Score:3, Funny)
>Seriously, though: where did all you sickos come from?
Apparently you've already forgotten that you are reading Slashdot.
so just turn (Score:2, Funny)
Increased Reliability? (Score:5, Interesting)
Re:Increased Reliability? (Score:2, Funny)
So what your'e saying is: The size of your "hard drive" doesn't concern you. You just want it to be in prime working condition when you do need it?
Bandage (Score:2)
Check out the DFI LANParty series of MoBos with RAIDx1.5 which allows pseudo RAID 0 and 1 with only two drives. Pretty durn click if you ask me, and not at a ridiculous price point either.
Just a though. (Doesn't actually FIX the problem though)
Re:Increased Reliability? (Score:5, Insightful)
I'd like to see Redundancy And Speed hit the consumer market more than the current volume. RAID 0+1 should be standard in at least mid level systems.
Re:Increased Reliability? (Score:5, Insightful)
You know, drive technology IS backup technology. Just backup data to hard drives instead of tape or CDs. Also, I believe a big reason is the density of data. No longer can you have something like floppies, where punching a tiny hole in the media won't cause a problem. Now, a speck of dust making a tiny microscopic scratch would ruin megabytes of data on a HDD platter, so they can't make unsealed media like DVDs or tapes that dense, now can they?
I personally never understood why sealed media never got popular. CDs with caddies would be far better, but people stuck with bare-assed, easily damaged CDs instead. Same problem with DVDs. Minidiscs aren't very popular unfortuanately.
It's possibly that tightly sealed media could be much higher capacity than currently seen, but who's going to be the one who suggests to their boss that they should try doing something that has failed every other time it has been tried?
Zip-style disks could potentially provide very high capacities, but they can't expand as quickly as hard drives... To do that, you'd need someing with it's own controller, like CompactFlash or hard drives.
I've said it before, and I'll say it again: "RAID is not a backup technology." When your main disk gets hosed by a virus, a clumsy user, or a system crash, that corruption is coppied to the other disc at light speeds... So what's the point? Offline backups are what is needed. RAID provides a solution for hardware problems, which is important with critical systems, but if the hard drive in my home PC crashes after a year, as long as I can restore a recent backup, and only be down for a few hours, it's not really a problem.
Re:Increased Reliability? (Score:3, Insightful)
Re:Increased Reliability? (Score:5, Insightful)
No, it is just a techical decision to do things that way... Hard drives are too bulky and expensive for small ammounts of storage, and tape drives are too expensive to have one tape per drive, not to mention the bulk.
In the real world, that isn't really the case. Your tapes are more likely to be damaged than a hard drive, mainly because the hard drive is extensively sheilded. Moving parts are only a problem after a long long run-time. If a hard drive's mechanical parts were working when you stored it, it will almost certainly work when you need to recover from it... Not to mention that hard drives CAN have everything but the platters swapped if you can find an identical device, or can be recovered manually by any simple data recovery center.
If you're talking about a live backup, you shouldn't be. One power surge could take out an entire RAID array. If you are talking about off-line, I have no idea why you bring up RAID.
Backup tapes are known to fail as well... That's why you make two of each, and send one off-site. Even if you aren't that stringent, your backup scheme should certainly have a LOT of redundancy in it, no matter what your media. I would certainly bet that hard drive failures are far more rare than tape failures.
PLAY (Score:3, Informative)
PlaY tried it. Remember them? They had a really neat technology - not bigger than CD but much, much smaller. It was self contained so you could toss a dozen in your pocket like coins. It was actually this close to being a killer technology, then they got too close to the RI
Re:Increased Reliability? (Score:2, Insightful)
Let's play a game of Find the Bottleneck!
Pentium 4 3.0C 800mhz CPU: 6.4 GB/s bandwidth
Sapphire Radeon 9800 Pro GPU:: 21.8 GB/s bandwidth
PC3200 DDR-400 RAM: 3.2 GB/s bandwidth
ATA/133 Hard Drive: 133 MB/s bandwidth
Now, I'm an avid gamer, and I fully realize that, comparing the performance, of, say, a video card to a hard drive isn't fair, because that video card has to do a lot more work than the hard drive, in a gaming environment. Still, when the video card's capable of pushi
Re:Increased Reliability? (Score:5, Informative)
Faster hard drives would need a faster bus to operate off. I went looking for a non-server board the other day with PCI-X (for gigE), and couldn't find one in a store.
Drives aren't the only bottlenecks.
Re:Increased Reliability? (Score:3, Insightful)
Not really. HD's are now more reliable than they've ever been; they're just a lot more common (9 HD's in my various systems at home now), and often not treated with the respect such precise electronics need.
Tips to making sure your HD's at least reach their design life:
Re:Increased Reliability? (Score:5, Informative)
Talk about ignorant moderation. Sheesh.
Hard Drives technology is very mature. Every innovation has involved incremental improvments to the same basic tech. So the notion of Hard Drives getting more high tech is false. Second, the reliability of Hard Drives has been steadily increasing in a nearly linear fasion since their introduction in the 60s. There has always been instances of a particular Drive model or model family having difficulties. These are special cases from a statistical point of view. Saying that these models represent the quality of all Hard Drives is like saying that terrorists represents all Irishmen. On top of this, many HD reliability issues are realy HD handeling issues, i.e. originating with the PC manufacturers, not the HD producers. So the second part of the statement is also false, in fact way false.
how will this effect the reliability of future drives?
If you bothered to read the full artical, you would know that one of the hold ups of this new approch is quality concerns. The HD manufacturers will not deploy it untill it is suitable for their high end ( i.e. most reliable) Hard Drive lines.
Comparing apples and hydrogen (Score:3, Insightful)
Because (Score:2)
They are both big changes in the way hard drives work that will lead to improved performance. They also talked about drive sizes changes (3.5in -> 2.5in)
Re:Because (Score:3, Interesting)
Bah, why always smaller???
Current HDDs store 50Gb/in^2, and area increases with the square of the radius. That single inch decrease results in literally half the platter area (not counting the spindle). OTOH, with even current areal densities we could have 1TB 5.25" HDDs. THAT would make me a happy consumer.
But no, that would make too much sense. Instead, they'll shrink the drive, requiring radical new (and untested in the wilds) techno
Re:Comparing apples and hydrogen (Score:4, Insightful)
An article which simply jumps into a description of an esoteric subject can seem awkward and be difficult to understand, so journalists have long been taught strategies for lessening that initial impact. Many of these conventions don't play as well in the internet environment because a linking page has already told the reader what the article will really be about. This makes the lead seem like irrelevant wandering.
Re:Comparing apples and hydrogen (Score:2)
And? (Score:5, Interesting)
Re:And? (Score:2)
A glance at the article would have told you that the interface changes that are going to be implemented before the perpendicular recording has everything to do with the speed.
Also, are you saying that "250 GB ought to be enough for anyone forever ?". They have hit a ceiling with the current technology and that is an understandable cause of concern.
Re:And? (Score:5, Insightful)
Not necessarily (Score:3, Informative)
The rotational speed of the drive is directly related to the access time. If the data you want is on the other side of the platter, y
Re:And? (Score:2)
I don't know if you can continue to spin disks as fast with longitudinal arrangements of bits, or if you can actually read 8 bits at once (perhaps not on the same head), but if you can this could be a substantial speed improvement.
Re:And? (Score:2)
Sag (Score:3, Insightful)
AFAICT, they're not talking about multi-layer recording, they're just standing the existing bits on end so that the same amount of magnetic material uses up less surface real-estate. <deadpan>If they did multi-layer recording, they'd have to slow the drives down so that the surface of the disk wasn't so stretched by centrifugal "force" and the shallower bits didn't sag into the next cylinder. Otherwise
Details? (Score:5, Insightful)
Are they using platters with trenches and storing information on the sidewalls?
Are they using some means of reading and writing at many depths within the platter without disturbing other layers?
The article says the technology has been under investigation for 20 years, so presumably there's a forest of technical literature on it.
Re:Details? (Score:5, Informative)
With perpendicular recording the bar magnet would be standing on it's end.
Longitudianl recording is like this:
Perpendicular recording is like this: Google is your friend... [google.com]Re:Details? (Score:2)
With perpendicular recording the bar magnet would be standing on it's end.
Ah.
Now I vaguely recall someone trying to market floppy drives that did that, about a decade ago.
Any numbers on what the minimum size of a domain is in each scenario? One of the papers the other posters linked put th
Re:Details? (Score:5, Informative)
Re:Details? (Score:2)
Re:Details? (Score:3, Interesting)
Instead of the magnetic field changes being lateral, they are vertical. Don't worry, the substrate is deep enough. It's really just another way to write smaller. Instead of long skinny areas being charged front to back, or back to front, the areas are oriented up and down.
Transition from 3.5" to 2.5"? (Score:5, Interesting)
HDD manufacturers said they expect to start replacing 3.5in. disk drives with smaller 2.5in. devices in enterprise products sometime within the next year.
Why would they want to do this? Has it something to do with vibrations (or even shattering a disk) due to the extreme rpm's that these drives are running?I don't know much about this stuff, so could someone please enlighten me?
Re:Transition from 3.5" to 2.5"? (Score:2, Informative)
Re:Transition from 3.5" to 2.5"? (Score:2)
Re:Transition from 3.5" to 2.5"? (Score:5, Interesting)
I like the move to smaller drives, This will be nice as people try to make computers smaller. I would also like to see a mini cd DVD format with mini cd drive only drives, shrink things up some more.
I'm curious when they will make platters about 1 inch across and stack them on a shaft a few inches long and lay them flat in a drive case, instead of a few vertical slow platters, a whole bunch of horizontal fast small platters.
The drive is the hold up in speed. It's the mechanical aspects that get hit by physics the most. When they get drives that go faster they can come up with a bus for it without much trouble. But currently why design a interface for HDs that can do say 1 terabyte/s if the drive can't even do 1/1000th of that. The electronics are simple, the drives arn't.
What ever happen to solid state drives?
Re:Transition from 3.5" to 2.5"? (Score:2)
What ever happen to solid state drives?
well, there's compact flash. it has a limited number of write cycles but otherwise you have one gig in the size of a postage stamp
there just hasn't been much demand for solid state drives. most people just use RAM. and RAM based drives are more expensive than RAM.
Re:Transition from 3.5" to 2.5"? (Score:2)
Disk kebabs (Score:2)
Drum storage [computer50.org] with a difference. At 10,000 RPM or worse, those suckers would precess [gsu.edu] like crazy. Perhaps they could use paired contra-rotating shafts [lineone.net], good bearings and hope nobody used them for a mobile app. Or build them into Segways. (-:
Back in the day (Score:5, Insightful)
Interestingly, my little 486 with its 340 MB drive were far faster than the old Sun, and even competitive with the newer SparcStations. 7200 RPM baraccudas in modified enclosures (extra fans and breathing holes made the difference between life and death) were even faster when they arrived.
After working exclucively with laptops for the past two years, I can see a clear parallel between the old 2.5" -> 2.5" transition and the 8" -> 5.25" -> 3.5" transitions in the past. Sure I keep a pair of 120 GB 3.5" disks in firewire enclosures around, but the 60 GB disk in my powerbook and the 30 GB disk in my Dell i8000 are more than adequate for daily use. My ipod even has 30GB, which is enough for my favorite music, the Warthog Jump video and a few other fun things.
With emphasis on blade and 1-U servers, as well as cardcage oriented telecom gear, I can see a lot of value for 2.5" disks in the telecom and server markets.
Re:Transition from 3.5" to 2.5"? (Score:5, Informative)
Why would they want to do this?
Average Access Time. Ever notice how it hasn't changed much in the last 20 years?
It was like 10-20ms in 1984 and is like 3-9ms now? No matter how fast you spin the disk or how much cache you add you still need to move the head from one side of the platter to the other. With 5" drives it was a little over 2" with 3.5" its a little over 1", with 2.5" drives 0.75" It's also true that if you make it smaller you can spin it faster, but I don't think 15,000 rpm is really hitting the limits of the materials or they would already have made the platers non-uniform in thickness. They could also go to single crystal metals like they do in aeroplane turbine blades (not so expensive to do in quantity.)
OTOH The disparity between bandwidth and access time is already embarrasing enough that I consider partitioning just half the space on my drives to improve access time. There are uses for big slow drives. For instance, things like audio and video if artists ever get their act together and jettison the media conglomerate dead weight they are carrying on their backs. Or for backups.
At this point GBs of hard drive space is like the Mhz thing was with processors. Most consumers just read the density and maybe the dBs and transfer rate, like they used to buy 900Mhz processors and get just 16 MBs of RAM when a 50Mhz Processor with 128MBs of RAM would have been literally thousands of times faster because they were thrashing with too little RAM. Buyers should look at access time, then transfer rate, and then capacity, unless it is for backups or some such tape replacement use. They should partition their drives because real-life filesystems still suck at placing frequently accessed data closely and contiguously for actual access patterns. If people realized this, hard drive manufacturers would do things like have multiple independent heads accessing the same platters, two would be easy, three could probably be done with current technology, and many more could be done with different mechanical linkages (for instance, screews might be slower and less elegant than an arm at moving the heads, but if you could fit fifty heads accessing the platters at once you would probably have better worst and average case access time.) This also would require updating some drivers, but I don't think it would take long considering the performance payoff.
interface changes (Score:2)
From the article - interface changes indicated in the writeup is going to be implemented very soon (could increase interface bandwidth from 20Mbytes/s to 320Mbytes/s !) while the perpendicular recording is going to take some time to hit the market.
Could someone explain (/point me to a website) as to what this paragraph means ?
"We always have concerns about new connectors and backplane designs but those problems are minimized in a seria
Re:interface changes (Score:4)
"We always have concerns about new connectors and backplane designs but those problems are minimized in a serial environment where the wiring is point-to-point,"
"Connecting devices fast is a lot easier when there's only two of them."
Re:interface changes (Score:2)
Re:interface changes (Score:2)
You can get around this to a large extent by having self-clocked encoding on each of the signal lines, and a data buffer at the end to line things back up (or a series of delay-locked loops to literally line the signals back up).
The popular parallel connectors (and buses) don't do this, tho
Adaptors (Score:2)
Density doubling annually; access speeds lag (Score:5, Insightful)
This conversation with Jim Gray [acmqueue.org], head of Microsoft's Bay Area Research Center, has grim, eye-opening comments on the growing gap between storage densities and access speeds/bandwidth. Currently the most effective way to send a multi-terabyte disk array is by UPS -- turns out a UPS truck has a "bandwidth" equivalent to about 7 megabytes/second. And the problem of practical access speeds is only going to get worse. At current and near-future access speeds, searching a 20-terabyte disk might take a year.
Re: (Score:3, Interesting)
Re:Density doubling annually; access speeds lag (Score:3, Interesting)
I agree on the raid stuff though. I think soon i'm going to start making all my computers with at least a raid 1 setup and even better a 0+1 setup. HD's are getting cheap. RAID interfaces are getting very common, and SATA seams to be bring RAID with it. 4 WD raptors in a box could make for
Re: (Score:2)
Re:Density doubling annually; access speeds lag (Score:3, Funny)
Re:Density doubling annually; access speeds lag (Score:3, Interesting)
That's assuming current speeds. Well, as data gets more dense, the access speed inherently gets much faster, assuming the RPMs stay constant. If physical size stays the same, random access can't really get too much slower. So what is it that is going to be bad about terabyte disks?
So what? All that means is that it's about tim
Re:Density doubling annually; access speeds lag (Score:5, Informative)
That's assuming current speeds. Well, as data gets more dense, the access speed inherently gets much faster, assuming the RPMs stay constant. If physical size stays the same, random access can't really get too much slower. So what is it that is going to be bad about terabyte disks?
The problem, as Jim Gray outlines it in the ACMQueue article [acmqueue.org]:
There's a lot more about this in the article. Check it out; it's +5 Informative stuff.
Re:Density doubling annually; access speeds lag (Score:3, Insightful)
At current and near-future access speeds, searching a 20-terabyte disk might take a year.
Today's drives run about 20 to 50 Mbyte/sec from the platter. You can get 133 Mbyte/sec from the tiny buffer, of course, but for a whole-drive search, let's assume you're going to read 20 terabytes at 30 megabytes/sec. My calculator says that's 666667 seconds, or 7.7 days. Yes, a long time to wait, but 7.7 days is a long way from "might take a year". Even if yo
Density is nice, but I need speed! (Score:5, Insightful)
In other news... (Score:2)
...engineers are working with software developers on a way to dramatically reduce power consumption by maximizing the number of 0-bits in memory.
"We think this could be a major breakthrough for laptop users dissatisfied with battery life," comments one developer who wishes to remain anonymous. "Studies show that modern software uses an increasing number of 1-bits, a side effect of the overcomplexity of today's lax programming standards and abundance of cheap, fast CPUs and RAM."
Sources indicate that in
Re:In other news... (Score:3, Funny)
Re:In other news... (Score:2)
Just switch from 1's and 0's to
Re:In other news... (Score:3, Interesting)
The grain of truth to this joke: There is a well-known technique that reduces the number of 1s in words transmitted on a bus by inverting words that are more than half 1 (and setting an extra bit indicating that the word has been inverted). The idea is to reduce the number of transitions on the bus lines, as a change in state is what dissipates power.
Re:In other news... (Score:2)
There was a funny story on a similar note from my hardware architecture class. The professor had been teaching about the various gates, and came to the NOT gate. The description given was "when the input voltage is OFF, the gate outputs an ON voltage". One of the students thought about this, and then asked the professor that, if this was the case, why couldn't you power a system by putting together a large quantity of NOT gates...
Other Three dimensional storage (Score:2, Interesting)
Of course, both of these are non-magnetic. And holographic memory is still research-only, as far as I know.
I wonder, will magnetic storage (in any number of dimensions) ever get eclipsed by non-magnetic ones like these?
Re:Other Three dimensional storage (Score:3, Interesting)
Maybe.
The disadvantage optical schemes have is that the size of a bit's worth of storage medium is the size of a wavelength of light. While magnetic media have limits too, the ultimate density limit for EM devices is the size of a small cluster of atoms (or even one atom) - much, much denser.
While holographic schemes store bits in a distributed manner instead of in individual buckets, the limi
Video Example of Holographic Storage. Excellent ! (Score:2, Informative)
http://www.inphase-tech.com/technology/
I'm not sure this will work (Score:5, Funny)
Re:I'm not sure this will work (Score:2)
Standing bits on end... (Score:4, Funny)
0
1
All of my bits will instead look like this?:
_
-
I suppose you can squeeze a lot more of them together that way, but is that really much of an innovation?
Now, if they had figured out a way to fold the suckers, I'd be impressed.
das shrunken (Score:5, Insightful)
April Fool? (Score:2, Funny)
how bits on end would work........ (Score:5, Interesting)
By the way, you can see old episodes of "The Computer Chronicles" at the Prelinger Archives collection.
http://www.archive.org/movies/prelin
I believe Slashdot had a story about that a while ago. Good stuff! Great info can be had through those old episodes about computer history.
Can we get real here (Score:3, Troll)
I cant help to see how this is not wasted time trying to improve the platter drives in favor of pushing out solid state storage faster. The advantages alone overrule more development on platter systems. Imagine instead of 100mbps of bandwidth on the hard drive you would be getting 10gbps of throughtput, no moving parts and much less heat and a longer MTBF time along with size alone this would blow away the server markets..
Who would care about the 16Gig memory limit when you have a solid state hard drive that ran faster than the memory array? Then you can just modify the software to use the Solid State Array (Think I'm going to patent this!hehe) SSA drive as memory and storage thus DB servers would have serious improvements compared to platter systems.
Re:Can we get real here (Score:2)
Because "solid state storage" to date has meant either battery-backed RAM, which is extremely expensive per gigabyte, or experimental optical or electro-optical approaches that aren't anywhere close to production.
There are plenty of companies within 2 years will have drives that will blow away current drives in speed and capacity. One such company is using nanotech to offer 1 terabit per cm2. And i
Re:Can we get real here (Score:3, Insightful)
there is no company who is reaching 1terabit per cm2, as there is something called the superparamagnetic limi
Damage potential.. (Score:2)
SealBeater
Hexagonal bits (Score:5, Funny)
See, there's a limit to how many bits you can store on a disk. I see. Because the area of the disk is limited I see. But you don't want a limit, you want more space. I want more space. But you can't have more space, because all of the bits are square they're square. and there's only so many square inches of surface. Only so much. Yes. Look at this disk. Radius 3.25" 3.25 It's a circle. It's round. Pie-R-square Pie-R-square So the area's limited. I see.
And the bits, they're almost square, because that's the way the manufacturers' engineers like them. They like squares? Yes. I see. Well, really they're not square, they're almost square. And how's that? Well, they're square sections of a round arc. Not square? But almost square. Almost square. I see.
So what do we do? I don't know. Well, we get a better packing fraction. Better packing fraction? Yes. That's the key. A better packing fraction. I see. And your data is round. Data is round Because the magnetic field is round. I see. And a square doesn't approximate a circle very well, does it? No. What does it better? A circle? Well, yes, but you can't do it with a circle, because circles bump each other. They bump each other? Yes, and they leave empty space between them. And we want a better packing fraction? Yes. So what do we take a cue from? I don't know. I know you don't know, but I'll tell you. We take a cue from the bee. The bee? The honeybee. He uses hexagons. Aaah. Hexagons. Yes, hexagons. They're all the future. The future? The future. The future. Yes, the future. Hexagons. Yes. That's where the money is. You're a nut.
What this MEANS (Score:5, Informative)
<- -> <-- -> <- -->
In the above diagram we're looking down at one track on the surface of a platter. Perpendicular recording works differently. The "magnets" or bits are arranged so that the field they emit is perpendicular to the medium, like this:
x . x . x . x
In the above diagram we're looking down at one track on the surface of a platter 'x' represents a field pointing away from us, '.' is one pointing towards us. This is what it looks like in cross-section (looking in from the edge of the platter):
^ | ^ | ^ | ^ | ^
| v | v | v | v |
In perpendicular recording the read head detects the actual direction of the fields emitted by these bits/magnets, rather than transitions in the field. Perpendicular recording is advantageous because it allows one to use a much smaller surface area on the medium for one bit. Imagine if you laid a line of bricks end-to-end on the ground, you could make the line shorter but taller if you stood each brick on end (so they're laid flat-to-flat), but you've not had to make the bricks any smaller in order to acheive this change in the length of your line.
Most of the above is hopefully right. Anyway it's a better explanation than that site gave.
A picture tells a thousand words (Score:3, Informative)
What a poorly researched article (Score:3, Insightful)
1. "As opposed to longitudinal recording, where the bits are impressed in a parallel format along the surface of a disc, perpendicular recording stands the bits on end, enabling more data storage per square inch."
What does it stand the bits at the end? I have never seend a standing bit. Especially on the end of it. Now c'mon, it could have been described a little more "technically". This is not USA Today.
And "impressed in parellel format" is such a crap of a phrase. It is not impressed, nothing touches, no impression, it is MAGNETIC, god damn!
2. "Apple Computer Inc.'s new G5 computers are all SATA-based while Intel systems will by the end of this year be based on the new interface."
Now this is utter turd. Before even G5 was announced, and probably before Jobs had the brainfart to invent them, some of the high-end PC motherboard manufacturers were already churning out SATA equipped motherboards. It was in the Intel development road map for several years now. I remember reading about it on Tom's 2 years ago.
Mr. Bolaji Ojo (EBN), please do your homework. Do not just blair (as in Jayson) out an article. You do wipe your ass after takin a sh*t, don't you? I am just asking that you would apply the same attitude toward writing articles. Thank you for your future cooperation.
A temporary solution, a fundamental problem (Score:4, Informative)
Although the solution proposed in the article would increase storage capacity by, say, a factor 2 or 4, it still is a temporary solution that does not solve the fundamental problem at hand.
The fundamental problem is the superparamagnetic limit: if you make a magnetic domain (a bit) smaller than a certain size, it becomes thermodynamically unstable. In English, this means that very small bits loose their value after a while. It also means that for the time being, we'll have to use tricks to pack the bits closer together while keeping them large enough to be stable.
It should be noted that perpendicular recording is not the only effort to achieve higher recording densities in the looming shadow of the superparamagnetic limit. Indeed, harddrive manufacturers have seen this problem coming for a number of years now, and have had meeting to discuss possible solutions [cnn.com].
On a brighter note, there seems to be progress in circumventing the superparamagnetic limit: very recent research [nih.gov] show promising results for the future.
Re:hmmm (Score:3, Insightful)
This is just my thought on what there doing.
Re:hmmm (Score:3, Insightful)
Think of matchsticks flat on the floor and standing up. The ones standing up will be further apart, or you could pack more in the same floor area and have them the same distance apart.
The difficulty is, matchsticks have an easily distinguishable top and bottom end, but magnet ends are only distinguishable by the direction of flux. The bottom ends are buried
Re:How exactly... (Score:2)
Perpendicular recording will be required at the point when products reach capacities of about 100- to 200Gbits per sq. in., compared to approximately 50Gbits today, industry observers said.
Got that? 2-4x. OK? Happy? Jeez.
Re:How exactly... (Score:4, Informative)
The "brick wall" in magnetic recording is called the superparamagnetic effect. This is the point at which the recorded data starts to get lost in the thermal noise of the media. (As you approach the superparamagnetic, it becomes statistically likely for recorded bits to sporadically flip states resulting in data corruption.)
For longitudinal recording technology, it is estimated that superparamagnetic will start to become a problem around 100Gbits/square inch recording density. (Current hard drive technology is around 50Gbits/square inch - so they are getting close to the wall.)
Perpendicular recording technology is estimate to scale up to around 1Tbit/square inch.
Now, what did I say about engineers liking to brag about 10x improvements? Well, 1Tbit is about 10x improvement over 100Gbit. How about that!
What this means to you: if current hard drives store about 120GB using a recording density of about 50Gbit/square inch, then we can expect perpendicular recording to eventually deliver drives that store about 2.4TB extrapolating up to a 1Tbit/square inch. Even if this technology only works half as good, at least we will eventually have hard drives that store 1TB!
On top of that, the article say they are moving away from 3.5" drives toward 2.5" even for "enterprise" applications. Now, if we get 1TB drives in 2.5" form factor that's going to result in some killer MP3^^err...uncompressed 24bit, 192kHz iPods
Re:How exactly... (Score:5, Informative)
Grrr, RTFA: there is nothing "3D" about it. It's still a 2-dimensional array of bits on a platter. The density increase comes from standing the little areas of magnetic media on end, instead of laying down. So, a top view of the old scheme would look like:
||||||||
||||||||
The new scheme, from the top:
In this case 2x density, as the lower one has twice as many dots in the same area as the dashes of the upper. (That is, each dot or dash represents the area of the physical medium used to store one bit by changing its magentic orientation). Get it? No 3-d. No holograms. Just 2-4x density increase by changing the orientation of the bits from parallel to perpendicular (relative to the disk platter surface).
Not quite - and HERE's why it's better than 2x (Score:3, Informative)
||||||||
||||||||
The new scheme, from the top:
In this case 2x density, as the lower one has twice as many dots in the same area as the dashes of the upper.
I don't think that's quite right.
Unless I missed a transition from longitudinal to transverse recording, the old scheme produced a track like this (viewed either from the top or side:)
N---SS---NN--------SS---N
The vertical scheme lays the magnets
Re:How exactly... (Score:3, Informative)
Both schemes store the bit to some depth physically. You can't have an infinitely thin bit. Both schemes also still use a 2-D grid of bits. (Well, polar grid, since it's a spinning disc.)
A truly 3-D organization of bits within a single platter face would be something like those multi-layer DVDs, where within the same grid position you can access multiple bits by changing some aspect of the reading mechanism. (In the case of the DVDs, it's achieved by focusing the lense differently so only the desire
Re:summary (Score:3, Informative)
It'd be more like:
from --------
to ||||||||
Perpendicular recording would effectively replace a two-dimensional bit with a one-dimensional bit, from the recording head's point of view. (Or something close to that.)