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WD Builds High-Capacity, Helium-Filled HDDs
Lucas123 writes "Western Digital subsidiary HGST today announced that after 10 years of development it is preparing to release 3.5-in data center-class HDDs that are hermetically sealed with helium inside. The helium reduces drag and wind turbulence created by the spinning platters, all but eliminating track misregistration that has become a major issue to increasing drive density in recent years. Because of that, HGST will be able to add two more platters along with increasing the tracks per inch, which results in a 40% capacity increase. The drives will also use 23% less power because of the reduction of friction on the spindle. HGST said the new seven-platter helium drives will weigh 29% less per terabyte of capacity that today's five-platter drives. In other words, a seven-platter helium disk will weigh 690 grams, the same as today's five-platter drives."
Those of you wondering why they don't just use a vacuum inside the drive. Hard drive heads ride on a cusion of air (or in this case, a gas of some kind) so that they don't crash against the drive.
Is this going to be cheaper than SSD? The price point for solid state finally reached where platter drives were about ten years ago (a dollar or less a gig) and I installed one on my system just last week as my OS drive. Also, are these going to be significantly faster than the standard five platter density drives? Frankly, weight only matters in tablets, phones, and laptops. I'm not aware of any crushing weight problems in the steel server racks...
Occasionally living proof of the Ballmer peak.
Yes yes, you have to watch out for that non explosive helium.
These disks are great except when you replay audio files the vocalists sound like munchkins.
Proverbs 21:19
In case anyone didn't get that, there's a worldwide helium shortage at the moment.
What about the impending Helium shortage?
http://www.popularmechanics.com/science/health/med-tech/why-is-there-a-helium-shortage-10031229
Helium was used as a lubricant in fixed head disk drives in the late 60's.
They had to keep a tank of it attached since it is very difficult to keep it from leaking out.
How, exactly, are they going to keep the Helium from leaking out?
*facepalm*
*hands over nerd card*
There's no place like
Argon walks into a bar. An alarm goes off and the bartender yells "Hey, we don't serve your kind here!" Argon, of course, didn't react.
Actually, you good-naturedly admitted your facepalm moment.
You may keep your card, good sir.
These drives are not the first. Circa 1969, Digital Development Corporation of San Diego sold a line of head-per-track disks that used a helium atmosphere. A typical unit took around 24 inches vertical height in a 19-inch rack. Given the difficulties of sealing anything against helium leakage, these drives required a small helium cylinder and pressure regulator to maintain a small positive pressure within the enclosure, and had a pop-off valve to vent excess pressure. The electronics consisted of about a dozen circuit cards built with discrete transistors. The capacities of these units were amusingly small by modern standards: the first one that I had direct experience with, held something like 128K bytes.
Sure they weigh less, because they are filled with helium. But when the servers start lifting off the ground and floating off, they might have to rethink this idea.
Likely to be a permanent condition.
Helium is light enough that it doesn't persist very well in the atmosphere(unlike the heavier noble gasses, that you can just distill out if the price gets high enough to pay for the energy needed), and it is only replenished quite slowly by alpha decay of assorted radioactives in the crust.
The only significant source is natural gas wells in proximity to suitable minerals over geologic time and equipped to capture the helium when the product is brought to the surface.
anyone buying these need to ask what happens when the helium inevitably leaks out...
No worries; when the balloon attached to the side is half-full you know it's time to replace the drive and then find a child to give the balloon to.
Or if you are not in a hurry take the drive in to any Party Center USA store for a free refill.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Liquid Helium sell for $8.00/L on the wholesale quantity market.
It is still very, very cheap.
Last fill on my MRI machine was 800L due to cold head failure. Lucky me I have a service policy, but still, that's a big use of Helium. I would not worry about your Helium balloon.
Bill
Another advantage of using a drive filled with helium is better thermal conductivity than air (0.142 vs 0.024) . The heat generated by the inner workings of the drive will be conducted to the outer case, keeping the inside cooler.
Yes. In chemists' jargon, "oxidation" is the process of giving away electrons. The process is named after the most common electron recipient, oxygen, but lots of molecules can be oxidizers.
Or to put it another way, if I mix hydrogen with oxygen, and you mix it with chlorine, and we both add a spark, we'll get pretty much the same effect. Either way, there'll be a tremendous bang, and neither of us will have any eyebrows. Of course, after a few deep breaths, your nose might start bleeding as hydrochloric acid eats your mucous membranes, but that's a separate issue.
Look up partial pressure in some physics book. If you have gas in some leaky container at some pressure, it doesn't matter that there is another gas at another pressure outside of that container. Even if the different gases are at equal pressure, what will happen is that each will diffuse into the other through the aperture. That diffusion depends just on the respective partial pressures.
Helium at a lower pressure does not face an uphill battle due to the excess pressure outside of the container. It just diffuses through the apertures in the imperfect containers at a lower rate due to its lower pressure.
What would slow down the leak would be if there was helium on the outside at the same pressure, because then there would be as much helium diffusing into the container as diffusing out. But there is very little helium outside the hard drive, it being such a rare gas.
I think that if the apertures in the leaky container are such that helium can escape, but air cannot get in, then in fact the container will slowly evacuate. Pressure in that container will gradually drop as helium escapes, while hardly any finds its way back in.