There are also physical changes. SMR and HAMR drives can pack up to 10 platters in a standard 3.5″ hard disk enclosure. There is no room for error with this level of packaging, and no room for heat. To reduce heat friction, the drives are filled with helium, which makes them cooler and less prone to overheating.
Because heat is such an issue, SMR and HAMR drives have a lower power draw than standard disks, so even though capacity is greater and there are more platters in the drive, SMR and HAMR drives consume less power per gigabyte.
They come with caveats, however. With so much technology packed into such a tight space, there’s greater opportunity for failure. While Western Digital and Seagate have undoubtedly tested the drives rigorously in their labs, it’s not until we have real world use cases that were going to know if the lifespan of these drives is comparable to a standard disk or not. No doubt BackBlaze will be on top of this issue with its quarterly hard drive failure reports.
Another negative for the new drive technology is a slower write performance. That’s a logical tradeoff given that the drives are packing more data per platter than the old technology. A performance hit is inevitable. The performance hit varies based on how full a drive is, because a drive has to essentially defragment itself every time it writes data. Fortunately, in their most common use cases – archival, mass storage, cold storage – write performance is less of a concern than read performance.
IT departments are gaining even more dense options with these new high-capacity drives, but there is cost in write performance, said Brent Ellis, storage analyst for Forrester Research. “So, this is really meant to address archive and low- to mid-tier storage needs. Higher performance storage will be on SSD and NVMe,” Ellis told me.
HDDs will long have a role in large, cloud-scale storage environments, but SSDs are catching up, he added.