Helium vs air-filled hard drives: does it matter?
Above roughly 10–12 TB, almost every drive you can buy is sealed with helium instead of air. Here's what that actually changes — and what it doesn't.
The one-sentence answer
Don't pick a drive based on helium vs air — pick it on capacity, recording type, workload rating, and warranty. At high capacities helium is simply how the drive is built; the benefits are already baked into the specs you compare.
Why helium at all?
Helium is about one-seventh the density of air, so the platters spin through far less drag and turbulence. That lets manufacturers pack in more, thinner platters — seven, eight, or nine instead of five — which is how drives reached 16, 20, and 24 TB.
The drives are hermetically sealed at the factory. There's no user-serviceable part and nothing to top up; the helium stays put for the life of the drive.
What it changes for you
- Lower power and heat. Less drag means less energy spent spinning and a few degrees cooler running — meaningful when you have eight drives in a NAS humming 24/7.
- Higher capacity. The headline benefit: helium is what makes 16 TB+ possible at all.
- Quieter, lighter. Reduced turbulence makes helium drives a touch quieter and physically lighter than a comparable air drive.
Is helium less reliable?
Early worry centred on the seal leaking, but years of large-scale field data now show helium drives are at least as reliable as air drives — often better, thanks to the cooler, lower-stress internals. Drives also monitor their own helium level via SMART (the Helium Level attribute), so a rare leak shows up long before it causes trouble.
What to compare instead
Spend your attention on the specs that actually affect your use: CMR vs SMR, rated workload, warranty, and price per TB. Browse high-capacity options on our price-per-TB leaderboard or the refurbished enterprise list, where most large drives are helium sealed anyway.
General guidance, not a guarantee. Always confirm the exact specifications for your model number against the manufacturer datasheet before buying.