It is exhausting to advance a expertise that might be going through obsolescence, however that is what Western Digital and its chief rival Seagate Applied sciences are doing. Laborious disk drives (HDD) have misplaced the low-end capability market to solid-state drives, and SSDs are slowly however absolutely making their method to larger capability dominance.
So, the makers of HDDs have caught to the one place the place they nonetheless have a bonus, and that’s capability. For an SSD to extend capability by 50%, it wants 50% extra chips, and which means a 50% enhance in worth. However exhausting drives, because of some technical wizardry, proceed to see a rise in capability and may now put 40% to 50% extra knowledge on a single platter than earlier variations allowed.
Western Digital unveiled the second technology of its Ultrastar DC HC680 drive household of drives in 24TB and 28TB capability utilizing shingled magnetic recording (SMR) expertise, which is designed particularly for knowledge facilities. It additionally launched new enterprise drives, the WD Gold Enterprise and Ultrastar DC HC580 24TB, with typical magnetic recording (CMR).
This matches Seagate’s high-end X24 drive, which tops out at 28TB and in addition makes use of SMR expertise.
SMR expertise – together with the heat-assisted magnetic recording (HAMR) expertise created by Seagate – represents a brand new technique of accelerating storage density.
The first distinction from older expertise is how the bits are organized and packed onto the disk platters. By means of superior electrical engineering, areal density (knowledge saved per sq. inch on a platter’s floor) may be elevated by as much as 40% inside the identical area as conventional exhausting drives.
There are additionally bodily adjustments. SMR and HAMR drives can pack as much as 10 platters in a regular 3.5″ exhausting disk enclosure. There isn’t any room for error with this degree of packaging, and no room for warmth. To cut back warmth friction, the drives are stuffed with helium, which makes them cooler and fewer liable to overheating.
As a result of warmth is such a problem, SMR and HAMR drives have a decrease energy draw than customary disks, so although capability is larger and there are extra platters within the drive, SMR and HAMR drives devour much less energy per gigabyte.
They arrive with caveats, nevertheless. With a lot expertise packed into such a decent area, there’s higher alternative for failure. Whereas Western Digital and Seagate have undoubtedly examined the drives rigorously of their labs, it is not till now we have actual world use circumstances that have been going to know if the lifespan of those drives is similar to a regular disk or not. Little doubt BackBlaze can be on prime of this situation with its quarterly exhausting drive failure experiences.
One other adverse for the brand new drive expertise is a slower write efficiency. That is a logical tradeoff on condition that the drives are packing extra knowledge per platter than the outdated expertise. A efficiency hit is inevitable. The efficiency hit varies based mostly on how full a drive is, as a result of a drive has to basically defragment itself each time it writes knowledge. Fortuitously, of their commonest use circumstances – archival, mass storage, chilly storage – write efficiency is much less of a priority than learn efficiency.
IT departments are gaining much more dense choices with these new high-capacity drives, however there may be value in write efficiency, mentioned Brent Ellis, storage analyst for Forrester Analysis. “So, that is actually meant to handle archive and low- to mid-tier storage wants. Larger efficiency storage can be on SSD and NVMe,” Ellis advised me.
HDDs will lengthy have a task in massive, cloud-scale storage environments, however SSDs are catching up, he added.
“Improvements like QLC have made capability flash arrays a risk, giving enterprises entry to moderately dense storage with an order of magnitude higher efficiency and considerably much less energy draw. I believe if you add in all of the components, capability flash begins to look very engaging and guarantees to shut the hole even additional. HDDs nonetheless win within the terabytes per {dollars} class, however I believe that point is restricted, particularly if you add in warmth, mechanical failure, and energy draw,” Ellis mentioned.
