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Consortium Roadmap Shows 100TB Hard Drives Possible By 2025
Lucas123 writes An industry consortium made up by leading hard disk drive manufacturers shows they expect the areal density of platters to reach 10 terabits per square inch by 2025, which is more than 10 times what it is today. At that density, hard disk drives could conceivably hold up to 100TB of data. Key to achieving greater bit density is Heat-Assisted Magnetic Recording (HAMR) and Bit Patterned Media Recording (BPMR). While both HAMR and BPMR will increase density, the combination of both technologies in 2021 will drive it to the 10Tbpsi level, according to the Advanced Storage Technology Consortium (ASTC).
MTBF and transfer rate numbers are boring... but those can be just as important, if not more, than the drive's capacity.
With high capacity tier 3 drives, one reason that RAID 6 (or a RAID 50 setup with tiers/groups of disks) is used is because it can take days to rebuild a blown drive. If drives continue to have larger capacities, but I/O stays the same, then we will need to add more parity drives to RAID arrays to support multiple drive failures and still keep the data accessible, better algorithms that run in the background to detect (and fix) bit rot, and bigger/smarter caches.
Maybe this is just me, but I'd rather see drives with double the MTBF than double the capacity. I can always add more drives and arrays. A failed disk will cost time no matter what, even if it is just walking to the server room, pulling it out and replacing it with a spare. For non-enterprise customers, a failed drive can be catastrophic since not many users have RAID arrays for protection.
Somewhat off topic, but while we're talking about drives:
We put millions of transistors on a chip. Millions of photodetectors (pixels) in your phone's camera, a million pixels on it's display. Yet our hard drives have ONE sensor that swings back and forth on a mechanical arm?!?! Why the heck isn't the read/write head a strip, with a few thousand "pixels", so it can read any sector as the platter spins beneath it, without swinging the heads back and forth? That would eliminate seek time.
If needed, you could move the strip back and forth a thousandth of an inch to align a head with one of it's four tracks. That'd be a lot quicker that moving the head a full inch as they do now.
So presumably there is some good reason that can't be done. Still, an additional arm exactly like the existing one, but on the opposite side of the platter, would cut rotational latency in half and increase throughout up to 100%. Seems like an easy win.