Western Digital just ramped up the capacity of its spinning disk hard drives by 2TB, thanks to an 11th platter. They’ve rolled out two new models: the 26TB DC H590 and the 32TB SMR (shingled magnetic recording) DCH HC690.
So, what’s the deal with SMR? It overlaps recording tracks, kind of like how a clinker boat is built. Each new track slightly covers the previous one. You can read from these drives without a hitch, but rewriting is more of a challenge compared to traditional drives. These SMR drives shine when it comes to sequential writes. Once they’re full, you wipe them clean and start fresh, much like working with tape. Regular drives, on the other hand, allow for writing and erasing whenever you want.
These drives typically spin at 7,200 RPM and connect via SATA at 6Gbps or SAS at 12Gbps. However, they don’t fully utilize the available bandwidth, which ranges from 600MBps to 1.2GBps. The HC590 can handle writes at 302MBps, while the HC690 manages 269.5MBps. That’s quite a bit slower than solid-state drives, which can max out that bandwidth, but SSDs usually cost over twice as much per gigabyte.
As for the competition, Western Digital might soon overtake Seagate. With SMR technology, they’re maximizing recording density by eliminating wasted space between tracks. They also employ energy-assisted perpendicular magnetic recording (ePMR), which has been in use since 2020. By using two electric charges at the write head, ePMR helps prevent the new data from interfering with the existing data on the disk. This precision becomes crucial as companies push for even greater track density.
Seagate has opted for a different approach: heat-assisted magnetic recording (HAMR). This technique uses materials that stay solid until heated up briefly during writing, making it easier to modify just the bits needed without affecting the surrounding data. Seagate is making strides with HAMR, set to introduce standard HDDs reaching 28TB or 30TB by the end of the year, plus SMR drives hitting 32TB or 34TB, thanks to their own 10-platter drives.
Toshiba is also in the mix, showcasing hard drives with capacities of 32TB and 31TB using heat- and microwave-assisted magnetic recording. Their biggest current model is a 22TB non-shingled MAMR drive. Seagate is certifying its 30TB and 32TB drives, both conventional and shingled.
Spinning disk drives continue to thrive, especially among big cloud providers. They’re often a more cost-effective option compared to flash storage, particularly for durable services like object storage, such as AWS S3. Recent data suggests a whopping 30 million hard drives are sold every quarter.