Unable to even come close to SSDs in terms of performance, hard disk makers have chosen to compete with capacity. A SSD over 1TB in size starts to become expensive, especially for consumers, so HDD makers Seagate and Western Digital have gone for massive capacity, introducing drives with up to 14TB of capacity.
But now Seagate promises greater speed thanks to a new drive head technology. Dubbed the multi-actuator technology, it’s a simple idea that’s been around a while but wasn’t economically viable in the past due to higher component costs.
Hard drive heads are connected to an arm called an actuator. This moves back and forth across the disk while the disk spins. Hard drives have multiple platters for storing data, and the actuator arms have drive heads on both sides of the platter, since data is written to both sides of the platter.
The actuators are all aligned and move together. So, even if you have a drive with three platters and six heads, covering both sides, only one drive head at any time is reading or writing. Seagate’s new design uses two sets of actuator arms that operate independently, so two heads can read at the same time instead of one. The drive can respond to two commands in parallel, so two heads can read or write at the same time, or you can have one reading and another writing.
Dual-actuator drive delivers data twice as fast
According to a blog post by Seagate, the computer sees the dual-actuator drive as if it were two separate drives, so it can perform two different data requests simultaneously — delivering data up to twice as fast compared with a single-actuator drive.
This will be important because the increase in hard drive capacity and the explosion of data means more and more time spent reading and writing to disk. Seagate is targeting 40TB drives by 2023, while its arch-rival Western Digital is aiming for 40TB by 2025. They can’t make drives spin any faster than 7,200 RPM without increasing heat and failure rate, and the SATA bus, while no longer fast enough for SSDs, still has plenty of room for HDD.
Seagate has a high-density technology in the works called Heat-Assisted Magnetic Recording (HAMR), set to launch next year and in volume in late 2019, that will deliver hard disks of 20TB and more. Western Digital has something similar in the works at roughly the same timeframe. These drives will have up to eight storage platters, and performance overall will suffer if the network is choking while waiting for data to load.
“Capacity is only half of the solution. If the ability to rapidly access data doesn’t keep pace with all that capacity, the value potential of data is inhibited. Therefore, the advancement of digital storage requires both elements: increased capacity and increased performance,” Seagate said in its blog.
The only way to make hard drives faster was to make them read and write faster without spinning the disk at a higher speed, so the multiple actuator drive technology makes sense. Seagate said it will be used in drives with eight actuator arms and 16 heads, meaning very high capacity drives. I’m sure this will eventually trickle down to 1-3TB drives used in the home, but for now this is poised to launch in the enterprise.