No-one doubts that IBM Corp has some of the best researchers in the disk drive business, and if only the company could transform their good works into products that won over the hard-nosed OEM disk drive buyers, the company would be the market leader in small disk drives instead of trailing way behind the likes of Seagate Technology Corp and Quantum Corp. Nevertheless, tomorrow is another day and for its latest trick, the team at IBM’s Advanced Magnetic Recording Laboratory in San Jose, California has demonstrated product-level components working together to write and read data on a hard disk at a density of 5G-bits per square inch. IBM says the test data was read at product-level speed of 10M-bytes per second with accuracy of one error in one G-bits. The demonstration used an advanced version of IBM’s magnetoresistive recording heads, an ultra-low-noise magnetic alloy disk coating and improved electronics using equalization techniques to enable all components to work together to achieve the desired high-speed and accuracy. In the demonstration, bits were stored at a linear density of 240,000 bits per inch along concentric tracks packed at 21,000 per radial inch. The bits are recorded onto a thin film of an ultra-low-noise, four-component magnetic alloy that coats the aluminium disk. The company first demonstrated 1G-bits per square inch in 1989 and launched the first product at that density last year – it’s Travelstar VP stores data at 1.44G-bits per square inch on two platters of a 2.5 drive for capacity of 1.6Gb in a package 0.35 thick. It hopes to get 3G-bits – demonstrated in 1995 – to market rather more quickly, and 5G-bits quicker still. The company’s spin valve heads, which use giant magnetoresistive effect, were not used in the latest demonstration: IBM sees these leading to capacities of 10G-bits per square inch in about three years.
