3 ms·

Gases have viscosity...

• astrodust 10y ago
  There is that factor, but how much heat do the heads generate, that's what I'm asking. The servo and associated electronics surely generate many orders of magintude more heat.
  • jdietrich 10y ago
    Air shear can generate a significant amount of heat. Reducing drag will also reduce the power requirements for the motor and voice coil. HGST claim a 23% reduction in operating power over air-filled drives. http://www.hgst.com/company/media-room/press-releases/HGST-Helium-Filled-HDDs-Rise-to-New-Levels-Achieve-Industry-Leading-Milestone-in-Field-Reliability http://www.hgst.com/company/media-room/press-releases/HGST-H... As I understand it, the crucial factor motivating helium-filled drives is the reduction of vibration due to internal turbulence. Reducing turbulence inside the drives allows platters and heads to be made thinner and packed more closely together without affecting reliability.
    • astrodust 10y ago
      Right, so it's the nature of the gas in terms of its viscosity and turbulence that's the factor here, not in terms of friction per-se.