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.