There’s an interesting article in The Register about Seagate developing hard disks with two independent sets of read/write heads. When you think about it, this is long overdue. Currently an eight-platter drive will have sixteen read-write heads. They all move in concert so that reading from a particular location means that all the heads are positioned over the same track waiting for the desired sector to spin past.
Seagate’s new implementation splits the head mechanism into two groups. If the disk can read or write to two locations simultaneously that’s already a boost to I/O capacity. The Register speculates that other manufacturers will jump on this trend and go further with multiple read-write actuators.
Seagate’s own blog post explains this further. As ever, this new innovation puts our lecture material out of date. In week 11 of Introduction to Operating Systems Virtualisation our students have just learned that the read heads move in sync. That’s another lecture to re-write next year. Computing always evolves and we have to evolve with it.