Most of today's non-solid state hard drives run on air. The read/write heads "surf" above the frantically spinning magnetic platters on a cushion of that breathable stuff, but the downside is that the heads bumble around a lot in all the turbulence. Western Digital is about to replace all that air with helium, massively increasing drive performance.
Helium is just one seventh the density of air. As far as hard drives are concerned, that makes a huge difference to all the insidey bits by drastically reducing drag. Reducing drag on the platters (which hold all of your data and are stacked up inside the drive on top of one another) as well as the read/write heads will have the following effects on the next generation of WD's hard drives:
- Platters can be thinner, meaning that the drives can weigh up to 29% less per terabyte of capacity. This means that a seven-platter helium drive will weigh about the same as a five-platter drive with air inside.
- Lighter platters with lower drag means less energy to keep the drive running. 23% less, to be precise. While idle, a five-platter drive with air in it consumes nearly seven watts, while a seven-platter helium drive will draw just a little over five watts.
- It'll cost you about half as much to buy a 3.5 inch helium-filled, seven-platter drive than it will to buy a 2.5 inch air-filled, four-platter drive.
So that's all great stuff, but the other important thing about using helium as opposed to air is that drive manufacturers have been approaching the limit of the amount of data that they can stuff onto magnetic platters. The way to fit more data into a smaller space is to fit the little bits of data closer together, which is fine, but at some point, the air turbulence inside the drive causes the platters and the read/write heads to wobble and shake enough that you just can't read bits reliably anymore. Using helium instead of air reduces the turbulence and solves the problem.
So basically, we're looking at drives that are faster, cheaper, cooler, quieter, cheaper, lighter, more efficient and cheaper. WD says that it's been working on this for the last ten years, and it's now confident that it can start producing hermetically sealed helium-filled drives by next year. Initially, the drives will be targeted at cloud computing systems and data centers, but since the concept is really a new technology platform as opposed to a product, sooner or later we'll be seeing these things in our desktop PCs as well.