6TB Helium-Filled Hard Drives Take Flight

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6TB Helium-Filled Hard Drives Take Flight

Posted by samzenpus on Monday November 4, 2013 @04:26AM from the building-it-better dept.

An anonymous reader writes in with some exciting news if you are a storage array manufacturer with a lot of money to spend on hard drives."HGST Monday announced that it's now shipping a helium-filled, 3.5-in hard disk drive with 50% more capacity than the current industry leading 4TB drives. The new drive uses 23% less power and is 38% lighter than the 4TB drives. Without changing the height, the new 6TB Ultrastar He6 enterprise-class hard drive crams seven disk platters into what was a five disk-platter, 4TB Ultrastar drive."

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What the helium actually does by TWiTfan · 2013-11-04 04:32 · Score: 5, Informative

Here is a relevant portion FTA on what the helium actually DOES (unfortunately not mentioned in the summary):

At one-seventh the density of air, helium produces less drag on the moving components of a drive - the spinning disk platters and actuator arms -- which translates into less friction and lower operating temperatures.
The helium-drives run at four to five degrees cooler than today's 7200rpm drives, HGST stated.

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1. Re:What the helium actually does by dcw3 · 2013-11-04 04:56 · Score: 4, Informative
  
  This might help you... http://en.wikipedia.org/wiki/Flying_height
  Heads fly, and you don't "fly" in a vacuum.
  
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Re:Helium Leaks by SternisheFan · 2013-11-04 04:38 · Score: 5, Informative

They do have a 5 year warranty.
10 Years of Research & unpressurised by tomxor · 2013-11-04 04:43 · Score: 5, Informative

They spent 10 years researching how to reliably seal it into an enclosure...
Also it is not under the same requirements of a compressed gas canister. The whole point of using helium is for the advantages of it's fluid dynamics compared to a normal air mixture, that's why it's not pressurised.
I've always wondered why they didn't just use a near vacuum enclosure, but i suppose it's much easier to not deal with pressure difference and use a super low resistance fluid instead at the same atmospheric pressure.
1. Re:10 Years of Research & unpressurised by SuricouRaven · 2013-11-04 05:01 · Score: 5, Informative
  
  They don't work in vacuum.
  Fluid interaction between spinning platter, gas and the heads creates an air bearing effect that holds the heads at a precisely determined (for a given linear velocity) height away from the disc. It's a stable system, so any slight vibration will be quickly compensated. Without a fluid filling, the heads would crash into the platter.
2. Re:10 Years of Research & unpressurised by ShanghaiBill · 2013-11-04 05:03 · Score: 5, Informative
  
  I've always wondered why they didn't just use a near vacuum enclosure
  Because the head would crash. The head does not just magically float a few micrometers above the disk platter. There is no way that any machine could be build so precisely. Instead of floating, it flies. The head is shaped like a tiny airfoil, and it use the ground effect of the air/helium/whatever to maintain the proper distance from the platter. This would not work in a vacuum.
3. Re:10 Years of Research & unpressurised by Solandri · 2013-11-04 07:37 · Score: 5, Informative
  
  They don't work in vacuum.
  That's true for a regular hard drive, but I'm not sure that's true in this case.
  
  e.g. A computer used at the ski resort in Mammoth Lakes experiences an air pressure about 25% less than sea level. So the volume of air inside the HDD enclosure wants to expand until it's 33% greater. With a regular HDD they just put in a filtered breathing hole to allow air in or out to equalize the pressure. This equalization is why the drive won't work in a near-vacuum.
  
  If they'd filled this with helium, I can think of two ways they're handling this expansion problem. They're either using a bladder with regular air inside, and the breathing hole goes to the bladder. That's the way we handled the problem in submersibles - oil compresses slightly more than water, so if you simply seal your thruster motors in an oil bath, the water pressure will crush them and cause the rotating parts to bind. Instead, you attach the oil reservoir to a flexible oil-filled bladder exposed to water. The bladder shrinks under pressure, equalizing the oil pressure inside the motor with the water pressure outside, without contaminating the motor with water.
  
  But since the HDD is bathed in a gas instead of a liquid, that wastes a lot of interior space - at least 33% if you want the drive to work at about 8000 ft, more if you want it to work higher. I'm not sure they have that much space available if they've crammed in 7 platters. So the other possibility is they've completely sealed the helium inside and the drive maintains the same internal pressure even at altitude.
  
  Either way, there's a minimum pressure below which the inside of the drive won't drop. In the latter case the pressure is constant. In the former case the minimum pressure is simply the pressure when the bladder is completely emptied of outside air - i.e. even in a vacuum there will still be pressure inside the drive. And if they're having to do that anyway, they'd be smart to make sure that low pressure was still sufficient to allow the drive to operate. That would make this drive the only (relatively) cheap large-capacity drive capable of being used in low ambient pressure applications which normally have to use flash storage or an SSD.
4. Re:10 Years of Research & unpressurised by MozeeToby · 2013-11-04 10:16 · Score: 4, Informative
  
  Very nice, insightful post, but not really what the parent posts were getting at. The original post that started the chain was something like "why don't they make the interior of the drive a vacuum rather than helium filled?" The answer was that the heads and the platters maintain proper distance using aerodynamic affects which wouldn't work if the drive were emptied of all air.
Re:Helium Leaks by nabsltd · 2013-11-04 05:49 · Score: 5, Informative

The dark underbelly of hard drives is you get a single replacement, the replacement has a 90 day on it and that's it.
Every Western Digital replacement drive I have received has had the longer of either the remaining original warranty or one year.
These are all drive in their "Black" line, so that might make a difference.
Re:Helium Leaks by Lord+Apathy · 2013-11-04 06:02 · Score: 5, Informative

You can get a REFURBISHED equal drive that has a higher chance of dying. Oh and the replacement has no warranty. The dark underbelly of hard drives is you get a single replacement, the replacement has a 90 day on it and that's it.
Not true. I had a seagate with a 5 year warranty go out 2 years into its life. The replacement had a 90 day warranty or what ever was left on the original warranty, which ever was greater.

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Re:Great... by ShanghaiBill · 2013-11-04 06:05 · Score: 5, Informative

Which makes me wonder WHY He and not Xenon or another far easier to contain gas.
Xenon makes no sense whatsoever. It is heavier and infinitely more expensive than air. It is also a poor heat conductor, which is why it is sometimes used in sealed triple pane windows. It would be a terrible choice.
The point of using helium is that it is light, has low viscosity, high thermal conductivity, and is cheap enough to use in party balloons. Hydrogen is better on all these counts, but leaks more easily, can chemically react with some lubricants, and causes metals to become brittle. The only reason to even consider using any other heavier gas, would be if even helium leaked too much. But apparently they have that problem licked. So helium wins.
Re:Great... by danlip · 2013-11-04 06:09 · Score: 4, Informative

This is not squandering, this is a good use and a great example of why we should not be squandering our helium reserves. And you could probably make a 100 drives for the amount of helium in 1 birthday balloon (the open space in a drive is a rather small percentage of the drive, which in turn is much smaller than a balloon).
Re:Great... by ShanghaiBill · 2013-11-04 07:06 · Score: 5, Informative

Not entirely true, hydrogen gas is pairs of hydrogens forming a molecule whereas helium is single atoms floating around making it much smaller and much harder to contain.
No, this is wrong. H2 is more permeable than He through almost any material. In particular, helium will not permeate through bulk metal that is carefully annealed to contain no microscopic cracks. Hydrogen, on the other hand, will slowly permeate directly through most (or maybe all?) bulk metals.
Re:Great... by Anonymous Coward · 2013-11-04 08:08 · Score: 4, Informative

" but leaks more easily"
No it does not. Helium is mono-atomic and has the smallest atomic radius of the mono-atomic gasses. This is why it leaks more than anything.
Hydrogen may be the smallest di-atomic molecule.
Re:The head never moves, the disk spins under it. by foobar+bazbot · 2013-11-04 11:11 · Score: 4, Informative

The head never moves, the disk spins under it. Putting a wing shape on the head wouldn't do anything.
It's too bad the disk doesn't drag some air along with it as it spins. If there was a layer of moving air along the boundary between the solid and gas, the heads could fly in that region.