WD Sampling its First Hybrid HDD

WD, a subsidiary of Western Digital Corp., is sampling a 5mm-thin HDD featuring hybrid technology.

WD has developed hard drives slim enough for integration into today’s thinnest notebook PCs, which provide capacity storage and robustness while featuring instant-on and application performance similar to today’s client SSD. The new technologies will be showcased during WD’s Investor Day, Sept. 13, 2012.

"Mobile devices are becoming smaller, thinner, lighter and more responsive," said Matt Rutledge, VP of client storage solutions at WD. "Working with our technology partners, WD has developed new 5 mm hard drives that enable high capacity storage along with excellent performance and superior economics to allow our customers to expand their thin offerings."

With device volumetric efficiency is a concern for system makers, WD began shipping 7mm height HDDs for thin-profile notebooks earlier this year (historically, standard notebook hard drives have been 9.5mm). 5mm hybrid hard drives will enable the market’s thinnest computers to offer 500GB of capacity, utilizing almost 50% less volume compared to current 9.5mm HDDs and at one tenth the cost of similar capacity SSDs.

"Acer is partnering with WD to bring advanced notebook performance and capacity in the smallest form factor," said David Lee, associate VP of Mobile Computing Product business unit at Acer Inc. "It’s a part of our ongoing commitment to present leading technology that ultimately improves the total user experience of our customers."

"We are seeing a shift in the computing world to more powerful mobile computing solutions," said SY Shain, SVP of ASUSTek Computer Inc.‘ notebook business unit. "With this in mind, ASUS and WD are collaborating to create slimmer and more mobile notebook solutions – without sacrificing capacity or performance – to deliver smaller form-factor to consumers."

Hybrid Technology and Client Tiered Storage
WD’s hybrid technology pairs MLC NAND flash storage for fast SSD-like data throughput and instant-on responsiveness with magnetic disks for efficient, capacity storage. Similar to the practice of multi-million dollar enterprise systems, WD’s hybrid technology utilizes the concept of tiered storage. Data accessed most frequently (often referred to as hot data) is managed using speedy NAND flash to ensure fast response times, while data accessed less often (cold data) resides on the magnetic disks. The tiered design of hybrid hard drives, compared to current dual-drive solutions, also provides a redundancy benefit for users. The magnetic disk backups all files residing in the NAND, protecting the user from inevitable NAND wear and preserving it for the more hot data handling. WD’s hybrid technology works in conjunction with the PC OS to deliver higher performance than current hybrid offerings while minimizing NAND wear to allow the use of less expensive MLC NAND.

Hybrid hard drives combine NAND flash and magnetic disks, simplifying storage-element integration for OEM customers and providing end user benefits: performance, responsiveness, lower power consumption, greater operating shock tolerance, and data protection.

And unlike dual-drive designs, WD’s hybrid technology provides single-unit design homogeneity for OEM system manufacturers.

Read also:
Toshiba Demos Hybrid HDD
1TB, 5GB cache
Toshiba and WD to Come in Hybrid HDDs
After Seagate and Samsung

Comments

New WD hybrid drive is not only the thinnest hybrid unit never introduced but also the thinnest 2.5-inch HDD never revealed.

The first 2.5-inch HDD were 19mm height.

Former record was 7mm (0.2 inch) z-height pushed by Seagate with the 250GB Momentus Thin in December 2009.
Hitachi GST is also in this tiny height since 2010 with latest version being the 500GB Travelstar Z7K500 revealed last February and more recently WD on Scorpio Blue also up to 500GB.

But the WD hybrid drive is not the thinnest HDD. Introduced last year, the latest 1.8-inch MKxx39GS devices from Toshiba, at 160GB, 200GB and 220GB, are also 5mm units but the WD device has the highest capacity in the word in this height.

It's possible today
to mix NAND flash and magnetic memories
with two different architectures:

Using two different physical units, SSD and HDD, into one unit with cache software.

Using only one device integrating the two memories and algorithms for caching like WD.

Seagate was the first one in 2006 into hybrid HDD with the Momentus 5400PSD (120GB). It was followed by Samsung one year later with the SpinPoint MH80 (also at 120GB). But they failed to be accepted by the market.

Seagate came back in 2011 with the 9.5mm 500GB Momentus XT and persevered last year with 750GB, the only ones currently offered since WD's announcement.

This idea of 5mm hybrid HDDs was apparently initiated by Intel at Intel Developer Forum last April for its 15m z-height ultrabook design.

wd_hybrid_5mm_foto_idf2010_540

It's a remarkable feat to pack 500GB in such a 5mm HDD containing (probably) one disk and two heads. Main challenge seems to be to scale the thickness of the spindle motor positioned in the center of the platter while maintaining the motor performance such as the non-repeatable run-out (NRRO). Singapore-based A*Star Data Storage Institute revealed last November said it aims to produce HDD with only 5mm thickness for tablets. Few months before, it signed a collaboration agreement with Taiwan's National Tsing Hua University (NTHU) to pursue research on flexible cable which will be assembled into 5mm hybrid HDDs, "targeted to launch at the end of the year."

But SSD's form factors can be slimmer, especially in mSATA form-factor. Among companies with 5mm SSD are Super Talent with its Masterdrive FTD30GK25H (30GB) and pureSilicon (128GB) on units introduced in 2008. Intel revealed in 2010 its 5mm Solid-State Drive 310 (mSTATA, 80GB, $170 in Q1,000). Transcend Information rolled out two years ago its mSATA half-slim SSDs (3.5mm, 64GB). These last two years Greenliant Systems reached even a thinner height 1.85mm, for its SATA SSDs (up to 60GB). SSDs in mSATA form-factors are even slimmer. But their capacity is far from 500GB with probably a much higher price per gigabyte compared to the new WD device.

Today WD is offering its hybrid drives to OEMs only. But it could build in the future special units for end users able to be inserted in their notebooks or sub-notebooks. Why not also an external device with a fast interface like Thunderbolt to use the device for primary storage?

WD didn't reveal some important specs:

Disk/heads: probably 1/2

Interface: probably SATA or mSATA

Rotational speed: probably 7,200rpm

Capacity of NAND MLC: probably 32GB, much more than Seagate culminating at 8GB but on SLC NAND

Source of MLC: probably SanDisk

Price: "Not yet – we are currently sampling to Acer and Asus – today’s announcement is more of a technology leadership news", according to a WD's spokesman.

Released
in

Company

Model

Capacity
(GB)

Other Specs

06/2006

Seagate

Momentus
5400PSD

40 to 160

80GB/disk, 256MB flash, 5400rpm, 3Gb SATA

03/2007

Samsung