Robert wrote:
Paul wrote in part:
HGST is owned by Western Digital.
The category is "Enterprise". 16TB for $577 USD.

They might have done HelioSeal before WDC did.
Unlike regular air-breathing drives (which use a breather hole),
the HelioSeal are sealed and have a Helium gas atmosphere
inside. Helium drives draw less power, or allow more platters
(with the platters eventually returning to glass, just like
IBM days - that's how they plan to make thinner platters).

Glass? Maybe OK for hoop stress at 10krpm (1.8 MPa / 260 psi)
but you might want to be careful with the jerk at spinup.

The Helium gas is guaranteed to stay inside for 5 years.

Why not Hydrogen? _Much_ cheaper and better properties.
Oh, yeah, invokes the LZ Hindenburg at the hands of Joisey
longshoremen (What are grounding strap?) But seriously, the
heat from that small a volume is less than in a cup of coffee.

Balloons should not be filled with pure hydrogen unless you are
real careful or making YouTube videobangs. In large numbers
they'd be a hazard especially with the static electricity.
Nor does Nitrogen dilution help much.

What part of that history sez "16TB for $79" ? :-)
Paul

-- Robert


I don't think hydrogen is quite as good for the
metals around it. Helium has fewer "side-effects".

As for the glass, we don't know what kind of glass
those platters are made from. I guess we'll just
have to get one of those $79 drives and open it up
for a look. They love the exotic chemistry, so just
about anything is possible. The surface finish has
to be smooth to about 2nm or so (at least, that's what
the MFM pictures look like, of the surface).

Paul