The personal computer marked 25 years of ever-more brilliant existence last weekend with a shadow of obsolescence hanging over its future. Suppliers such as Dell, Hewlett-Packard and Lenovo Group face slowing sales growth and pressure on profit margins while consumers are turning to more innovative and less complex devices. About 1.6 billion PCs have been sold in the 21/2 decades since IBM launched its benchmark product in the United States and 870 million are installed worldwide, according to researcher Gartner. Annual revenue for the industry has grown to US$200 billion, helped initially by the PC's ability to harness the power of software and later the internet. Yet the dazzling adaptability of a machine that has come to play a central role in people's lives at both work and play may lead to its demise. 'The virtuous circle of innovation that drove the PC has become a vicious cycle of increasing complexity,' Gartner said in a report this month. 'Simplicity and stability are key PC failings.' Enterprises find that PC configuration and operational maintenance lead to operating expenses that far outweigh original capital costs. Consumers also wanted devices that simply needed to be switched on to work, Gartner said. Smart phones, with advanced software and hardware configurations, are sometimes cited as PC replacements. 'The growing availability of cheap, ubiquitous bandwidth and processing power, coupled with internet-based services, makes possible a new style of application delivery,' Gartner said. More importantly, the PC market is facing intense competitive pressure. 'We will once again see a buyer's market for PCs, as in 2001-2002,' said Gartner, which predicted three of the top 10 PC vendors would exit the market by next year. Attrition is already under way, with China's Lenovo completing its US$13 billion acquisition of IBM's PC business in April last year.