This week Seagate announced a performance breakthrough for future HDDs: Their Multi Actuator technology. In the past years we could see HDDs being more and more pushed aside by SSDs and M.2 drives when it comes to performance. While capacitys increased steadily to tackle an increasing amount of data and sizes read and write performances did not change quite as much with data density and rpm of the disks being, until now, the only factors manufacturers tried to increase to get higher transfer rates. And thanks to the noise disks with higher rpm produces there were some caps with that never were touched. So HDDs became more of a pure storage devices for large amounts of data but if you wanted speed, you stayed away from them. So the options until now were either going for an affordable drive with much bytes per dollar (HDD) or for optimal performance that has a hefty price tag per byte.
Now Seagate is trying another way. Traditionally HDDs have a single actuator that navigates all r/w heads in unison across the disks. Therefore hindering parallel requests as well as IOPS by more than just a bit. With the first installment of the new technology Seagate will use two independent actuators that navigate half of the heads and they promise up to twice the performance of a current single-actuator drive. While the technology itself looks like a very nice approach the performance part should be taken with a grain of salt.
It’s absolutely true that you can then use a disk in parallel (if the data of two requests isn’t located in the disks of the same actuator). But sadly for sequential operations of a single thread the speeds won’t be affected by this at all. IOPS will most likely be somewhere in between and you still have to factor in the rotational delay as well as seek times to get to the correct position of the data you want.
In any way even if the claims of twice the performance turn out to be pure marketing the technology itself is a step in the right direction for sure and we can hope for further advancements in this field in the future. Perhaps HDDs will someday be viable for demanding tasks again.