6 ms·
You'd certainly expect the long-term failure for Helium filled to be lower. By displacing (moist) air, you've completely stopped any metal corrosion. Helium is
by jarvist 8y ago
You'd certainly expect the long-term failure for Helium filled to be lower. By displacing (moist) air, you've completely stopped any metal corrosion. Helium is also highly conductive to heat, so you will even out any hot spots.
Does anyone know to what sort of pressure helium the drives are filled?
- Someone 8y agoMy thought when first hearing about them was that, having an extra point of failure (Helium leakage), they would have higher long-term failure rates.
- thatcat 8y agoIf that leakage only brings the probability of failure back to previous rates, then you've still lowered the failure rate overall.
- teilo 8y agoNo, that's not what would happen. Helium drives enable higher data density, because helium decreases the amount of drag, which in turn reduces turbulence, platter vibration, and heat. This enables more more platters per drive and more accurate head positioning. Helium leakage would make the drive substantially less reliable than air drives due to the higher data density.
- derefr 8y agoBut they're not comparing denser helium-filled drives to less-dense air-filled drives. They're comparing 12TB helium drives to 12TB air drives—equal density. (I have no idea how they're managing to make non-helium drives of that density, but apparently they can.) Of course, for a drive density that can only be achieved using helium, a helium leak will kill the drive. But right now, it seems that these drives might not actually need the helium, since equivalent drives exist without it.
- Terr_ 8y agoFWIW a quick search suggests the 8TB drives have the same RPM too, so it's not like the helium-drives are running faster just because they can. (Helium-filled HUH728080ALE600 versus air-filled ST8000DM002.)
- thatcat 8y agoTechnically, you could choose a 3.5 inch, 6 Gb/s, 4 Tb model that contains He and then compare to the non-He version.
- deleted 8y ago[deleted]
- tedunangst 8y agoIs the thermal conductivity of helium actually relevant to hard drives? Like what kind of hot spots and transfer rates are we talking about?
- HankB99 8y agoFWIW utility generators are cooled with hydrogen to reduce windage losses and promote cooling. Hydrogen is probably lower viscosity and higher thermal conductivity than helium. It's also very hard to contain due to the small molecular size and has the widest flammability range of any gas with which I'm familiar, making it an interesting gas to work with. ;)
- frandroid 8y agoThe utility generators probably don't worry too much about leaks, since they can just refill with new, abundant hydrogen, too. It would be amusing to have a hydrogen-cooled hard drive for which you'd have to regularly refill the water tank so that it could generate more hydrogen for itself. :)
- deleted 8y ago[deleted]
- tzahola 8y agoYeah, and it would have a little Bunsen burner to safely get rid of waste hydrogen!
- HankB99 8y agoYes, it's the hydrogen that leaks out that's the problem. I was told that the way to find hydrogen leaks in plant piping was to walk the line holding a corn broom over the line. When it bursts into flame you found the leak. In an enclosed space it can form an explosive mix with air if it doesn't ignite before it accumulates.
- fnordprefect 8y ago
- jammi 8y agoI don't know for a fact about the pressure, but I assume it's at atmospheric pressure, to make sealing and such less of an issue than making the HDD a pressure vessel.
- zeristor 8y agoHelium gas being conductive? Usually fluid cooling works by convection, isn't conduction only for solids?
- btrettel 8y agoFluid dynamicist here. "Convective" heat transfer includes heat transfer by both advection (the bulk fluid movement) and conduction. You might think convection is just advection, and I will admit the terminology is used inconsistently.
- zeristor 8y agoErm, I'm a lapsed physics graduate. Thanks for the correction, I was also watching PBS Space Time on Red Dwarfs, and how small stars cool the core by convection. Larger stars use radiation in the core and so lose access to a majority of the mass of the star which could have been used for fuel.