2.5" Hard Drive Shock (Gs)

[ryoken]

as u know, most 2.5" notebook hard drives are quite rugged relative to the 3.5" desktop hard drives. The Seagate Momentus 5400.3, for example, can sustain an operating shock of 350Gs. Could someone put into context (or an example) when the hard drive reaches 350Gs? What height does it need to be dropped to reach 350Gs? What about the surface on which its dropped?

 

[chcarnage]

A normal pen can experience up to 500 g after falling down from a desk, depending on the collision angle and the properties of the floor. The inflicted acceleration will be much lower on carpet than on hard floor. Hard floor pretty much means instant stop and this normally equals said acceleration of up to 500 g (I recall this number, hope it is right).

This high number is the reason why there's still a market for disks with free fall sensor for headcrash prevention.

 

[ryoken]

thanx for those figures! i guess that given the weight of a hard drive, then a drop from a desk would be much much higher than 500Gs... even the 900Gs non-operating shock of the Seagate Momentus 5400.3 will not suffice, right?

 

[chcarnage]

The acceleration (and deceleration on impact) of a hard drive and of a pen are the same if we neglect air friction, which is irrelevant at this height. I just wrote about the pen because the 500 g number comes from the mentioned pen example. A good impact angle may halve the maximal deceleration and a carpet helps, too, but all I know is that "dropped hard drives experience hundreds of g"... If you want to know more precise numbers you have to search for them, sorry.