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WD Announces 8TB, 10TB Helium Hard Drives
Lucas123 writes: Western Digital's HGST subsidiary today announced it's shipping its first 8TB and the world's first 10TB helium-filled hard drive. The 3.5-in, 10TB drive also marks HGST's first foray into the use of shingled magnetic recording technology, which Seagate began using last year. Unlike standard perpendicular magnetic recording (PMR), where data tracks rest side by side, SMR overlaps the tracks on a platter like shingles on a roof, thereby allowing a higher areal density. Seagate has said SMR technology will allow it to achieve 20TB drives by 2020. That company has yet to use helium, however. HGST said its use of hermetically-sealed helium drives reduces friction among moving drive components and keeps dust out. Both drives use a 7-platter configuration with a 7200 RPM spindle speed. The company said it plans to discontinue its production of air-only drives by 2017, replacing all data center models with helium drives.
Clever materials choices and lower pressure than on the outside (~40% IIRC). Luckily leakage is easily measured in the product design and testing phase, as well as ongoing QA. So not nearly as much risk to your data as stupid firmware bugs that only turn up under some circumstances after lots of usage. And no, they won't be refillable.
I was also wondering this. Wouldn't nitrogen or argon/neon be cheaper?
The point of using helium is NOT that it is inert, but that it is low density (although the inertness is also nice). Neon is five times as dense and far more expensive. Methane is four times the density. The only gas lighter would be hydrogen. But hydrogen has a nasty habit of migrating through metal, leaking out, and embrittling the metal in the process. Low density gases reduce friction both through reduced mass, and a higher speed threshold for laminar (rather than turbulent) flow. Low density gases tend to also be better heat conductors, helping to keep the disk cool. That is why high density gases, like xenon or sulfer hexafloride, are used in insulated windows.
That's almost exactly how it works with our quarter million dollar SANs.
They get paid to maintain the SAN and regularly visit to swap hardware bits or apply software patches to it.
Rod Taylor
Yes, sealing of the valve is a non-trivial issue, but it clearly can't possibly be an insuperable problem. Every K tank of compressed helium gas produced since the 1920s has such a valve, and those tanks are pressurized to well over 100 atmospheres. I have had such a tank sitting for over 10 years with negligible leakage as measured by gauge pressure. I did learn to my dismay that if you leave the main valve open and rely on the regulator and balloon-blowing attachment to hold, you will wonder where the gas went within weeks to months.
It would be interesting to know the pressure these drives operate at. If it is just room pressure, then I don't see how you could refill it unless you had an outgress valve as well as an ingress valve, in order to flush it.
So how does that work?
The helium in the atmosphere slowly dissipates into space. But it is also replenished by helium leaking out of the ground, where it is generated by radioactive elements emitting alpha particles (which are helium nuclei). At about 5.5 ppm, the source and drain are in equilibrium.