Bigger and Better Drives

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In addition to speed, drive capacity has also experienced continual growth over the past few years, and the race continues. Everybody knows all about the Intel vs. AMD sprint for the CPU holy grail of the time — the 1-GHz processor. Once the dust settled on that race a couple of years back, another race started up at once to exceed 2 GB of storage capacity. Most recently, the computer world just witnessed another contest to determine who would be the winner of the 3-GB dash. It has been pretty much the same among disk manufacturers, who keep announcing bigger and better disks, with capacities now reaching well over 100 GB. Seagate, for example, has already begun shipping its 180-GB Barracuda 180. By the time you read this, we will no doubt be well beyond the 200-GB barrier. It is not surprising that Gartner Group predicts that, based on the current annual doubling of capacity, 1.44-TB disks will be on the market by mid-2004.

Recent Developments

Recent developments will help manufacturers reach this level. During 2001, Maxtor, Microsoft, Compaq, and others announced a new interface standard for ATA hard drives (called "Big Drives") that will allow the drives to scale from the current limit of 137 GB up to 144 petabytes. Maxtor has released a 10-K SCSI hard disk drive, the Maxtor Atlas 10K IV. This will be quickly followed up with a 15-K class drive. Both drives incorporate Maxtor's second-generation U320 SCSI interface. The 10-K drive has an average seek time of 4.4 ms and a sustained data rate of 72 MBps. At the time of writing it was available in 36-, 73-, and 146-GB capacities. Seagate then set an areal density storage record — over 100 billion data bits per square inch (100 GB/in.²) using a magnetic recording head and multilayer antiferromagnetic coupled (AFC) disc. In effect, this allows 125 GB of data to be stored on a single 3.5-inch platter, compared with the current 40 GB.

Seagate also demonstrated the industry's first native serial ATA hard drive implementation at a recent PC Expo in New York. The companies connected a new Barracuda ATA V hard drive incorporating a native serial ATA interface running at full speed to an Intel motherboard in a PC game box. The serial ATA interface provided a throughput of 150 MBps. This breakthrough is expected to allow more complex, flexible, and intelligent storage systems. This serial ATA hard drive could also see a major change in the data center. Until now, companies preferred disk arrays configured with SCSI-attached drives for the storage of mission-critical data. Lower cost ATA drives were mainly used in PCs but tended to miss out in servers and particularly in data centers due to performance and reliability limitations. That may be changing, as the likes of EMC and Network Appliance are releasing ATA drives inside storage devices using serial ATA technology. This effectively boosts data throughput from 100 MBps for a parallel ATA drive to 150 MBps for the moment, moving up as high as 600 MBps within a couple of years.

Other companies such as 3Ware (Sunnyvale, California) are planning to release serial ATA RAID controllers and drives that offer performance similar to a SCSI while prices remain in the ATA price range; however, it may be a while before serial ATA catches up completely with SCSI, so the use of SCSI-based RAID will likely still dominate for the immediate future.

Fujitsu Drives

Another company at the forefront of disk innovation is Fujitsu. This company has quietly moved up to number two in the enterprise hard disk drive market and is rising rapidly. According to Gartner Group, Fujitsu now ships 21.3 percent of the world's 19 million enterprise class drives. Some of its most recent product offerings focus on removable and mobile disks, while others are suitable for enterprise servers.

2.3-GB MO Drive

A removal storage solution from Fujitsu, the 2.3-GB magnetic-to-optical (MO) disk drive is ideal for backup. It offers a data transfer rate of 8 MBps.

2.5-Inch MHS Mobile Disk Drive

The Fujitsu MHS Series 2.5-inch disk drives feature up to 30 GB per platter data capacity, a 9.5-mm form factor, fast Ultra ATA/100 interface, and 4200-rpm spindle speed.

15-K MAS Series 3.5-Inch Disk Drive

The Fujitsu MAS series disk drive is a high performance enterprise server and high-end workstation type of disk. This drive achieves areal densities of 33.1 GB/in² and 15,000-rpm rotational speed. It has an 8-MB cache buffer with 32-bit path for faster data access. An Ultra 320 SCSI interface offers host data transfer rates of up to 320 MBps. Average seek time is 3.5 ms, with a mean time between failures (MTBF) of 1,200,000 (although this does not mean that the universe will end before one of these disks will ever fail; see Chapter 3).

Upcoming Fujitsu Read Head and Media Technologies

Fujitsu also has some exciting developmental work ongoing in the hard drive field. It has developed new read head and media technologies, for example, that will provide hard drive recording densities of up to 300 GB/in². Though still in the prototyping stage, they are expected to be in full commercial deployment within two or three years. The new head, for example, features a current perpendicular-to-plane mode, giant magneto resistive (GMR) head that achieves more than three times the playback output levels of current hard drives by allowing current to flow perpendicular to the GMR element. Existing GMR read heads operate in the current in-plane mode and are not expected to scale beyond about 100 GB/in² areal density due to their small signal output level. In support of these developments, Fujitsu also just announced a linear density of over 1 million flux changes per inch on synthetic ferromagnetic media with longitudinal recording, making possible greatly expanded areal densities.

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