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.
Reducing drag on the platters will also allow HGST’s new helium drives to use 23% less spindle power to turn. A five-platter drive today draws 6.9 watts while idle. The new seven-platter helium drives will draw 5.3 watts of power in the same state.