4 ms·
Why would the platters be generating heat? By definition there's no physical concact with the heads, ergo minimal friction. I thought the primary reason for usi
by astrodust 10y ago
Why would the platters be generating heat? By definition there's no physical concact with the heads, ergo minimal friction. I thought the primary reason for using a monatomic gas was it would allow the heads to fly closer to the metal.
- lutorm 10y agoGases have viscosity...
- astrodust 10y agoThere 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 agoAir 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 agoRight, 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.
- drivethrowinguy 10y agoAbout ~3/4 of the power a drive uses goes into the spindle motor. Only a relatively small part of that is dissipated in the bearings (a quarter or so), all the rest is gas-platter friction, turbulences due to the heads etc. Fun-fact aside: The head fly height in helium drives is ~1 nm.