Cringely's Shameless Self-Promotion 225
wild_berry writes "The latest edition of Bob Cringely's column at pbs.org, entitled Shameless Self-Promotion: Bob's Disk Drive is up. He's talking about replacing the glass or metal platters in present hard disk drives with foil platters in order to save energy." From the article: "The materials cost more but we use so much less of it (the disk is so incredibly thin) that the total material cost is substantially less. This 'floppy' material has the same kind of magnetic coatings used on standard disk drives and our drives live on the same technology growth curve as those others. The way we obtain greater storage density is simply by putting more platters in a drive (say 12-15 instead of 4-5 in an enterprise 3.5-inch drive) because they are much thinner and can be stacked closer together. The only parts of the drive that are significantly different are the platters and the heads and the heads vary only in having an extra slot."
Quick... (Score:5, Funny)
How is this saving energy? (Score:3, Informative)
How?
With my primitive understanding of physics, the power required to keep something at constant velocity is basically the sum of the parasitic losses (in this case, aerodynamic and frictional losses). Changing the weight of the platter does not have much impact on energy consumption *except* for periods of acceleration (e.g. - the first couple of seconds during power-on).
Has my logic failed me here? How
Re: (Score:3, Interesting)
Too floppy (Score:2, Insightful)
just spin them all the time (Score:2)
Just keep 'em spinning all the time to keep them in a nice flat disc.
Re: (Score:2)
Re:just spin them all the time (Score:5, Funny)
The Gyroscope Effect (Score:2)
And???? Due to the significantly decreased mass of the platters, isn't this much less of a problem now?
Re: (Score:3, Insightful)
Re: (Score:3, Informative)
The article is admittedly short on specifics, but I imagine they'll be forthcoming, since he also mentioned that we'd actually be
Re: (Score:3, Insightful)
How much energy did you need to keep 1 TB of data online in 1980?
How much does it take today?
I would say the disk drive mfgs. have done their part.
Re: (Score:2)
btw an answer to the sig: I was at Ardis Hall drinking wine with Noman.
Re:The Gyroscope Effect (Score:5, Informative)
Not sure who the multiple HDD vendors are that will be introducing it next year, but I'm sure they asked a lot of questions about that, too.
Centrifugal force (Score:5, Informative)
In my lab we coat floppy materials (like plastic) in a spin coater at several thousand RPM. At that speed the disk may aswell be rigid.
Re: (Score:2, Interesting)
From the article: "the nature of our flying heads is such that dust is sucked away from the head-disk interface, meaning the drives do not have to be assembled in a clean room.". So presumably any dust that does drift onto the platter simply doesn't cause enough of a turbulance problem.
Re: (Score:3, Interesting)
The arm holding the read/write head sits in the middle of what would otherwise be a nicely rotating flow between the platters. The Reynolds number for flow between platters in a disk drive is going to be something like 30 m/s * 0.001 m / 2E-5 m^2/s = 1500 >> 1, so vortices will be shed off the back of the arm. Which basically means turbulence.
Incidentally, this is currently one of the limits to
Re: (Score:2)
"...the flexible metal foil yields to the head, pushed away by a layer of compressed air, rather than being struck by it."
My guess is that, at least for data centre applications, the power saving he claims for this design does not come from the lower mass of the platte
Re: (Score:3, Informative)
Uh no, not a safe assumption. Unless you can protect it from all corrosion - clearly not possible - then the interior of the device will actually produce dust... especially since there's a bunch of moving parts.
Move it and it dies... (Score:5, Insightful)
The hub now has to transfer a force rectangular to the foil-plattern's surface - fast - to tilt the rotating plattern inside the drive.
But the foil-plattern want to stay where they are (think bicycle wheel)
A foil doesn't provide much resistance rectangular to it's surface. The process is called "folding" if done exactly or "crumpling and head crashing" if done in a foil-platter-drive. Maybe it would even be called "cringling" then?
Do I make any sense to you?
Coincidently the CAPTCHA for this posting was "weakness"
There is no Centrifugal force! (Score:2)
I think you'd best watch what you say on slashdot. Some engineer might hear you utter those words, and then horrible things could happen. One time I heard a story about a guy who said something about centrifugal force while he was having dinner in a restaurant; an engineer happened to hear him and he killed the whole town in a fit of rage!
*hides*
Re: (Score:3, Informative)
According to TFA, they'd use extremely strong materials like Stainless Steel or Titanium to ensure the rigidity of the disks. They claim that this would be just as shock resistant as a Flash drive, but with faster seek time. (i.e. the lighter weight would mean less inertia to fight against)
Re: (Score:3, Interesting)
Re:Too floppy (Score:4, Funny)
*ahem*
According to TFA, they'd use extremely strong materials like Stainless Steel or Titanium to ensure the rigidity of the disks. They claim that this would be just as shock resistant as a Flash drive, but with faster seek time. (i.e. the lighter weight would mean less inertia to fight against)
Re: (Score:2)
Re:Too floppy (Score:4, Funny)
I'm not sure. Did I mention that they'll use the strength of Titanium or Stainless Steel to ensure rigidity similar to that of thicker aluminum or glass platters?
*snap*
I knew I forget something.
Re: (Score:2)
Re: (Score:2)
Indeed. The idea is that it will be able to "give" a little to prevent crashes, while still being strong/rigid enough not to shear off from gyroscopic forces. If one platter were to actually fold into another (or worse, the casing) at >10,000 RPM, then lots of bad things would happen to the poor drive.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Thanks to your suggestion, I just did. (Score:3, Interesting)
The disk is very floppy. The metal center is the only rigid part. The floppy plastic of which the disk is composed does not flop because it is too small, measuring only 1 3/16 of an inch from the metal hub.
Flimsier disks & MTBF? (Score:5, Insightful)
And what do these thinner materials and more closely-spaced heads do for the MTBF and error rate in such drives?
Re:Flimsier disks & MTBF? (Score:2)
Re:Flimsier disks & MTBF? (Score:3, Funny)
Re:Flimsier disks & MTBF? (Score:3, Insightful)
Re:Flimsier disks & MTBF? (Score:3, Insightful)
aluminum: 69
common glass: 70 to 95
stainless steel: 190 to 200
titanium: 406
So, titanium is almost 6 times stiffer than aluminum. I'm guessing that stainless steel has fair internal damping, which might reduce wobble propagation. (I'm not a mechanical engineer.)
Disk stretch? (Score:2)
I'd like to know how resistant the disks are to stretching over time due to the very high RPMS.
Re: (Score:2)
Re:Flimsier disks & MTBF? (Score:2)
I have that information stored here on an Iomega Zip disk. Let me just pop it in so I can look it up...
*click*
*click*
*click*
Aw fuck.
My first concern... (Score:5, Insightful)
That's quite a bold claim! If his claims are accurate, then we may be looking at the future of hard disk drives. Micro-disk drives would become the latest hotness, and Flash would disappear entirely from our memory. IF the technology works, that is.
Time and speculative investors will tell if it's really everything it's cracked up to be. I certainly hope it is, but extraordinary claims require extraordinary evidence.
Re: (Score:3, Interesting)
Re: (Score:2)
Re: (Score:2)
I hate spinning disks too, but they are the fastest, cheapest and most durable thing we have for big storage right now, unfortunately.
Seeing is believeing, so Mr. Cringely better be showing in that promis
Re: (Score:2)
I would assume that, like pretty much all hard drives, there's heads on both sides of the media, and both heads are pushing on it. As the disc approaches the head, the air pressure probably builds up more (like ground effects, but a different force AFAIK, or at least a different cause behind it) so it's pushed away. Thus if it floats one way, it gets pushed away from that way, and they tend to self-center. Thus instead of the head being positioned (as in a disk with an array of rigid platters) the discs ar
Re: (Score:2)
Secondly, the quote you chose - while stating that they believe it is more restant
Re: (Score:2)
This is true. However, my specific concern was in the foil bending. We've already got fairly good technology to prevent head crashes on a rigid disk. The question is one of seemingly flimsy foil bending toward a destructive end. According to TFA, they're going to use very rigid materials like Titanium or Stainless Steel to prevent it from being too flexible.
Re: (Score:2)
Would it ? Or would it simply develop bad sectors where the head struck, with
Re: (Score:2)
Re: (Score:2)
0.85 inch? (Score:2)
WTF? (Score:2)
Re:WTF? (Score:4, Interesting)
The real savings comes from the fact that the coating/finishing of the platters can be done on a big roll of foil and the platters can then be just stamped out. Standard platters must be finished individually.
Re: (Score:2)
He just gave a talk on this... (Score:4, Informative)
Cringely's time machine (Score:3, Informative)
Re:Cringely's time machine (Score:5, Informative)
Re: (Score:2)
Re: (Score:2)
That's not so hard to deal with actually. Have a few marker bits at the start of each track which tell you what track you are currently on and provide you with rotational timing and have a bit of code which compensates for being off a little bit because of temperature effects. Te
Re: (Score:2, Funny)
Are you suggesting I RTFA?!? Egads man, are you insane? Just imagine the implications if we all RTFA! There would be no threads like this, Slashdot would shrink to a mere story-posting site, moderators would be begging in the streets, we'd all have lives - the horror...!! [sob]
Re: (Score:2)
Both companies were around long before that. (Score:2)
Scanning/Tunneling Magnetic Drive (Score:2)
This kind of tech has a lot of problems in signal/noise, permissivity/permeability,
Re: (Score:2)
That's an ingenious idea. Technology like that would make existing hard disks last a lot longer, because the only moving part would be the spinning of the disks. That would prevent a lot of head crashes, and also increase the operating temperature
Re: (Score:2)
I'm still waiting for HD makers to "invert" their tiny feature-size manufacturing from platter surfaces to read/write heads. Why not a top layer disc that is covered with sensors/probes the same scale as the data domains on the discs below them? Addressing the probe layer with/for data as a RAM page, with a "layer index" for the target disc layer on which the proble layer "focuses". Maybe a single layer at a time, with the probe s
Re: (Score:2)
Speed control (Score:3, Interesting)
The only real power savings would come during spin-up. Once the disk is spinning, there's no additional power used to rotate a heavy vs. a light flywheel. (Well, a little bit because of increased bearing friction, but it's probably negligible.)
Finally, if you lighten up the parts in a hard drive, most companies are just going to use the energy savings to drive the parts FASTER.
IANADDEBIAAME*
*I Am Not A Disk Drive Engineer But I Am A Mechanical Engineer
Re:Speed control (Score:5, Informative)
You need to supply a constant input of angular momentum to keep the discs spinning. Spinning a
smaller mass will ALWAYS mean a lower power input, from start to finish and everything in betweeen.
Re: (Score:2)
All I'm
Re: (Score:2)
Parent said: "Once the disk is spinning, there's no additional power used to rotate a heavy vs. a light flywheel."
Mass is irrelevant when maintaining a constant angular momentum, all else (like coefficient of friction) equal. Once spinning, aerodynamics and friction are running the show.
Re: (Score:2)
Mass is irrelevant when maintaining a constant angular momentum, all else (like coefficient of friction) equal. Once spinning, aerodynamics and friction are running the show.
Except mass is related to the frictional force stopping it. Directly proportional in fact. The only question is how much drag is created by friction, and how much is created by the air resistance? I don't know, but if most of the drag is created by friction than a much lighter platter is going to have a lot less drag on it, and thus
Re: (Score:3, Informative)
Not exactly true. Remember that the coefficient of friction is just a imensionless scalar value, it is not the actual force of friction. You need to multiply the coefficient of friction by the normal force between the two objects that are moving past each other. In this case we are talking about the mass of the flywheel acting upon its pivot point. I believe the relationship of friction to the
Re: (Score:2)
"Finally, if you lighten up the parts in a hard drive, most companies are just going to use the energy savings to drive the parts FASTER."
If they drive the parts faster then you have greater performance. Energy costs vs performance, an old decision.
Re: (Score:2)
Exactly. My point was that the article makes it seem like you will get all of these improvements together, which is probably not true. Manufacturers will come out with hard drives that fit in the existing price structure. They will juice performance and capacity, but probably at the expense of potential energy usage. Also, these drives sound more complicated (if just because of the higher number of platters) - so that violates KISS and makes me suspicious of any
Re: (Score:2)
I have no doubt that hard drives will get lighter, faster, and maybe even cheaper. They will also use less energy in certain configurations. However, a data center is still going to buy the biggest, meanest, most dense hard drive that they can buy. The companies that make these will exploit the lighter materials to make the drive FASTER, not to use less energy. I suspect that t
Old technology new again? (Score:3, Insightful)
Ah, Wikipedia - http://en.wikipedia.org/wiki/Bernoulli_drive [wikipedia.org]
Basically, this drive is similar, just in a self-contained format rather than a removable cartridge solution?
Though, bumping the drive while spinning could do a lot of damage from precession of the platters causing the material to warp. Fast spinning disks are miniature gyroscopes.
Re: (Score:3, Informative)
that's the size and thickness of a credit card with a smartcard contact point on it for
the crypto control on the disc. 100Mbytes to over 5Gbytes in a device allegedly more durable
than Flash (it's got the same vibration, etc. characteristics supposedly, but it's write
endurance vastly exceeds Flash right at the moment...)- in a credit card's space. What Bob
did was suggest that they apply the tech to fixed disc devices-
I was always under the impression... (Score:2)
I also seem to remember that glass and ceramic platters don't expand as much as metals do during thermal change which happens a lot as drives are turned on and shuts down, so I'd wager that his idea of using tin foil, aluminium or any other metal is flawed. Seriously.
Re: (Score:2)
Who Died and Made Cringely Hari Seldon? (Score:5, Interesting)
In particular, I'd like to see evidence for the following claims:
I'd sure like to see the assumptions and numbers underlying that equation. Gee, Cringe, which do you think costs more: The raw platters themselves, or the read/write heads? I would say the latter. So you're going to drop the costs of hard drives by doubling the most expensive component? Huh? Sorry, I'm not buying this at all. You don't think a non-cleanroom enclosure is going to result in data loss on the platters themselves? Even if you're not getting particles during the read/write phase itself, you're getting them on the platter. I'm not buying the logic here. Sorry, I'm not buying this at all. Until the advent of true Drexlarian nanotechnology, I doubt you're going to see a mechanical action (you still have to move the eread/write heads) beat an eletronic one (reading from Flash).I'm not saying that the technology Cringely talks about is impossible, I'm saying: A.) There seem to be a lot of unwarrented assumptions underlying his logic, and B.) Implementation always has unforeseen hurldes and obstacles that will make these drives seem like far less of a slam-dunk vs. current technology (or more specifically, where regular drive technology will be 18 months from now) than it appears.
Finally, once it is ready, I'd like to see real-world tests for speed/electrical consumption metrics with existing technology. There might indeed be some savings, but I seriously doubt they are as dramatic as Cringely claims.
Crow T. Trollbot
Re: (Score:2)
Re: (Score:2)
Put your money where your mouth is (Score:2)
I see this solution to be prone to data errors. Therefore, I suggest that the vendor puts their money where their mouth is. Put them in some dozen tablets at a college for students and test the fail rate. Stick them in a SAN for a large data center and test the mean-time to failure. Hell, run Slashdot on them. I want to see failure, power consumption, and shock test data.
Re: (Score:2)
www.storcard.com/ (Score:2)
related: heads (Score:2)
I've always been curious - why don't modern drive have a spiral array of heads per suface, instead of the slower mechanical heads? It seems like track-seek speeds would disappear in such a design. Is the cost of a drive head than great, and how much of that cost is due to the movement mechanism itself?
Not everybody will be in trouble (Score:3, Insightful)
First thing flash has over this technology is *proven* reliability. This new technology can't buy that for money nor love.
Second thing is that this technology has *nothing* over flash (except maybe extreme temperatures, but special flash chips exist too). Performance is not said to be better than flash (you can't beet nanoseconds to access data in flash).
The only thing it has over flash at the moment is a cheaper price. Have you seen flash price trends over the last two years? I would say that it roughly obeys an inverse Moore Law (where prices for a same capacity are halfed every 18 months).
Flash chips are nothing but plastic and silicium. If Sandisk our however started feeling some heat from this new technology they could *ALWAYS* lower the price, hoping to make it up in volume.
At the moment flash manufacturers are at max capacity and are structuring their prices to maximise profit IN THE CURRENT MARKET CONDITIONS. If a new competitor comes out with a ground breaking technology they will find a new price point to maximise their profit then.
Flash, inlike hard drives cost almost nothing to produce, their marginal cost is virually pennies, unlike tens of dollars for HDs. They currently support investment costs and high margins, but in a differnet market configuration they could outprice these new disks and ramp up production.
Flash is the future, its already here but the chip companies have no incentive to make it any more affordable than it currently is, they are milking us just like OPEC does with oil.
If somebody invents tomorrow a car that recharges in 3 mins and has 500 miles range and same performance and price as regular cars, the oil barrel will drop to $15 overnight, it's the same thing.
It's all about supply, demand and marginal costs.
Nothing new.... (Score:2)
I think he can use the same arguments to justify making automobiles out of tinfoil instead of all that nasty costs-too-much-energy-to-move heavy metal.
Re: (Score:2)
Actually, it's not tinfoil, but you can make automobiles lighter and safer if you make them from carbon fiber and titanium than if you make them out of thin recycled steel as we do now. In fact, the cars of today are much smaller and lighter than the cars of forty years ago, yet they are also much safer. People said that replacing the heavy mild steel wit
Re: (Score:2)
Actually, they are less safe (more likely to be smooshed like a bug when hit by a semi), flimsier, and have too little cargo room. (bigger cars could have much larger crumple zones!). That is why SUV's got so popular. The CAFE laws prevented the auto companies from making cars in the classification "automobile" that people wanted, but there is a loophole that considers the car-like mo
Re: (Score:2)
Re: (Score:2, Informative)
Re:less energy consumption ? (Score:4, Funny)
Actually, modern revolving doors have a breakaway feature so traffic can go straight through in emergencies. If you try hard enough it is quite possible to slam one.
Just thought you would like to know.
Re: (Score:2)
Well, I guess it would depend on how many sections got slammed, rotational momentum, etc. Then there's the whole sort of existentialist thing about it being a revolving door when the slam started, but maybe not by the time it finished.
Failed physics? (Score:3, Informative)
Re: (Score:2)
Sure, the relative speeds are highest at the end, but >90% of the friction does NOT happen on the outer edge.
Re: (Score:2)
The read/write heads will disrupt that air flow, but I did note I was assuming they were out of the way.
Re: (Score:2)
A disk made from thinner material will have less weight, especially if the material has the mass properties of, oh, say titanium (which if you RTFA, you'll find out that titanium and stainless steel were the two metals they were working with). Less weight means you need a smaller motor to spin up, and a smaller motor means less weight and heat, and less power requirements. A smaller motor and light disk mean less friction. Put it altogethe
Re:Failed physics? (no) (Score:3, Informative)
Not failed physics... this is a flawed analysis.
There are a few different types of drag (I am an aerospace engineer). The relevant one in this case is caused by the surface of the platter, not the edge. Remember, the edge is really acting as if it were stationary - it's not moving the disc laterally thru the air, so the edge is irrelevant. Instead, the disk surface moving past the air drags some of th
Re: (Score:2)
Btw, Physics 101 called and they are interested in your no-friction disk platters for their student's lab experiements.
The spinning foil platter problem... that's (fairly) trivial mechanical engineering. I'll trust the fo
Re: (Score:2)