Helium allows the heads to fly closer to the disc,
This has been said over and over again - and NOT the main point. Because the gaps between the heads and platters can be closer, this means they can fit 1, maybe 2 additional platters inside the HD case. It does NOT mean if the helium escapes, suddenly the drive becomes useless.
Helium also allows the platters to spin with less friction between the platters and the helium gas molecules. This means it takes less energy (about 25% less) to spin the drive. When a data center has 100s, maybe 1000s of drives, those energy savings add up. Also, less friction means less internal heat. Less heat reduces cooling costs.
IT IS CRITICAL to note, while turbulence "
may" be an issue, that does not mean it "
will" be an issue should air get in there. To suggest that, all of a sudden, if there is a leak the platters are going to start flapping about like a wobbling frisbee about to fall out of the sky, and start banging into the heads is once again, nonsense.
Disk platters are extremely rigid disks being spun by extremely stable motors made with precision bearings designed to vibrate as little as possible.
To be clear - I am NOT saying nothing will ever happen should the helium suddenly escape. I am saying air getting in there will not suddenly cause the drive to vibrate itself to death as some here seem to be suggesting - assuming a quality drive in the first place.
air will cause all sorts of read/write errors as the heads will be further from the surface.
Huh? Nonsense.
For decades and decades hard drives had air in them - without "any" sort of read/write errors. Most hard drives today still have air in them and are not causing all sorts or any sort of error.
Should a helium drive leak and air gets in there, the read/write heads won't suddenly move further from the surface.
Don't need a clean room for the older drives if your just getting the data off.
Clean rooms have ALWAYS been preferred, and always been used in professional data recovery centers. That said, older drives didn't have helium so that point is moot in this discussion.
I read online that helium will escape after 5 years
It is important to read these claims carefully. To suggest helium "will" escape is not correct. I suspect the claim really says something along the lines of the helium is guaranteed to last for at least 5 years. WD says the helium "
remains contained within the drive throughout its operational lifespan", but does not define how long that is. I will note many of their drives have a 5 year warranty so I suspect that is where that 5-year value came from.
Hydrogen can pass through steel (given time), so I imagine Helium will eventually make its way through rubber seals.
I doubt they use "rubber" - certainly not in its pure form as even monster air molecules can easily pass through rubber. Just ask any cyclists who has to top off his or her bike tires every couples days due to the rubber inner tubes leaking like sieves.
That said, is is important to remember the helium inside drives is NOT under pressure, "trying" to get out, as they are in a bicycle tube under 120psi of pressure.