Western Digital this week disclosed several important details concerning its hard drive roadmap at the 5th Annual Virtual Wells Fargo TMT Summit Conference. The company is optimistic about demand for HDDs for years to come and expects its current technologies to deliver drives with capacities of up to 30TB in the coming years. However, it will eventually need to shift to heat-assisted magnetic recording (HAMR) technology. What is surprising is that the company no longer talks about its microwave-assisted magnetic recording (MAMR).
22TB for 2022
There are two general ways to increase the capacity of a hard drive. One is to install platters with higher capacity, which sometimes requires the usage of new magnetic recording technology (e.g., HAMR) and multiple new components along with new disks. Another way is to install more platters, which requires a transition to thinner platters and sometimes to different mechanical components. Makers of hard drives usually combine approaches, so over time, the industry transitions both to new magnetic recording technologies and to platforms with more disks.
The most advanced HDDs from Western Digital — the Ultrastar DC HC560 20TB and the WD Gold 20TB — use nine 2.2TB platters, energy-assisted perpendicular magnetic recording (ePMR), and OptiNAND technology. But apparently, the company already knows how to add 10th platter platform that can provide 22TB of storage if Western Digital decides to proceed with the same disks.
"We are able to deliver our 20TB on nine platters, we can add the 10th, and we get another 2.2TB of storage," said David Goeckeler, chief executive of Western Digital (via SeekingAlpha).
Up to 30TB with ePMR and OptiNAND
Western Digital's HDDs with OptiNAND technology adds an iNAND UFS embedded flash drive (EFD) to boost performance, reliability, and usable capacity. Western Digital will continue using this technology with ePMR. The company will also mate it with shingled magnetic recording (SMR) technology to provide some extra capacity to customers who optimized their software for SMR.
Western Digital believes that its ePMR and OptiNAND technologies will enable it to build HDDs with up to 30TB capacity. That figure is quite impressive as it requires the company to increase areal density of its platters by 36% over the next several years as well as increase the number of disks to 10. But from 30TB and upwards, Western Digital will need to use HAMR technology.
"So, we really have that staircase to take you to 30TB and then you get on the HAMR curve and you go for quite a bit longer," said Goeckler. "So, I think it is a really good roadmap for the hard drive industry."
No Mention of MAMR
What is a bit surprising is that Western Digital has not said a word about its MAMR technology that was meant to drive the capacity of the company's hard drives all the way to 40TB. Western Digital has always considered its ePMR technology to be an intermediate step between regular PMR and MAMR, which would eventually be replaced by HAMR.
The fate of MAMR is unclear at the moment. However, based on the fact that Western Digital no longer mentions the technology, it looks like ePMR will precede HAMR, whereas MAMR might not see the light of day at all, at least as far as Western Digital's drives are concerned. Yet, we are awaiting clarification from the company.