This month Hitachi Global Storage Technologies will begin shipping the first 7,200-RPM disk drive for notebooks, adding enhanced storage capabilities to the small market of mobile workstations.
The new 60-GByte Travelstar 7K60 drives will use a new "femto" slider, upon which the read/write head is mounted. Shrinking the slider reduced its size and weight compared to previous versions, allowing the head to move more quickly from track to track on the platter.
Most importantly, notebook OEMs will not have to sacrifice lower battery life to incorporate the new drives. HGST executives said that the power constraints of the new Travelstar drive will be the same as the companys 5,400-RPM products. HGST also announced an 80-Gbyte 5,400-RPM drive, the 5K80.
Both of the new TravelStar drives will be sold to IBM, which will incorporate the 5K80 in its ThinkPad notebooks next month. IBM will ship the faster 7K60 drives in a several ThinkPads shipping later this summer.
HGSTs new 7,200-RPM drives will serve a niche market, HGST executives acknowledged. "The market here is not large," said Bill Healy, general manager of the mobile business unit at HGST. "We started off at zero, and it may only be 5 percent over time. But this is the high end."
HGST will list the 7K60 at a suggested price of $300, the same price as the 80 Gbyte 5,400-RPM 5K80, basically asking OEMs to trade off an additional 20 Gbytes of capacity for the extra performance, Healy said. OEMs will receive additional discounts for buying in bulk, as they usually do.
"Its definitely going to be a niche market," said Dave Reinsel, research analyst for disk drives and components for analyst firm IDC. "Whatever goes into the mobile arena right now is going to be reserved for high demand. The bulk of the industrys still at 4,200-RPM, so it must still gain traction. Nevertheless, it is an interesting drive and opens the door for new technologies such as femto heads and their potential migration to the desktop."
The femto head, a designation agreed upon by the International Disk Equipment Manufacturing Association (IDEMA), is one of the few components within a disk drive that can take advantage of the constant improvement in wafer manufacturing techniques.
The slider head is actually part magnetic recording head and part aerodynamic wing. Grooves on one side of the slider buoy the head up, compensating for the assemblys weight, while similar grooves force it down so it can remain within the limits of the magnetic fields required to read and write data—just 0.23 mm above the surface of the rapidly spinning disk.
A lighter slider can be more quickly moved across the surface of the disk, but the lighter mass also means moving the slider assembly requires substantially less power.
The tolerance is crucial—if a laptop is jostled hard enough, the head can crash into the surface of the disk, damaging the surface and perhaps the head. But the femto sliders low mass, 0.6 milligrams, helped improve the nonoperating shock tolerances of the drive to 1,000 Gs non-operating shock and 200 Gs of operating shock, according to Randy Simmons, director of head technology at HGST.
Eventually, the femto slider technologies could be added to other HGST drive products, including desktop drives, and an "extended availability" model for blade servers and other devices. Currently, only about 1 percent of HGSTs TravelStar drives ship into the blade server market, Healy said, a segment that never took off quite as expected.. Seagate Technologies said Monday that it plans to design a line of 2.5-inch drives for use in the server market, beginning in 2004.