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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.
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.
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.