Sources at Taiwanese supply chain makers revealed to DigiTimes that Western Digital now plans to start volume production of its 5mm thin HDDs due to positive response from notebook makers and original device makers (ODMs). Previously, WD said it would start mass production in early 2013. The 5mm HDDs are about the same size as thin solid state disks, and will be used in the thinnest ultrabooks. Regular notebooks use 2.5" HDDs with a thickness of 9.5mm, while ultrabooks currently use 7.5mm thick HDDs. The new 5mm HDDs will be more expensive than 7.5mm models, but only 10 percent the price per gigabyte of SSDs.
While HDDs used in conventional notebooks are typically 9.5mm thick, HDD vendors have developed 7.5mm HDDs to suit slim ultrabook models, the sources indicated. As Intel requires reduced thicknesses for ultrabooks, WD has been making R&D efforts to reduce HDDs from 7.5mm to 5mm, the sources noted. Taiwan-based vendors Acer and Asustek Computer have adopted WD's 5mm HDDs and started design-in, the sources indicated.
5mm HDDs involve technological breakthroughs in components and manufacturing processes as well as modifications testing and specification certification, the sources pointed out. The cost of 5mm HDDs is expected to be higher than that of 7.5mm models and estimated to be 10% that of SDDs, the sources noted.