When IBM ( IBM) chief Sam Palmisano predicted at its annual meeting this week that the tech industry can keep out-revving the economy, he got lots of head nods. Despite persistently weak demand at the moment, pro stock-pickers, analysts and economists alike think tech can grow faster than the rest of the market. But there's a growing consensus that it won't be by much, particularly for the hardware business. And with growth likely to be much tamer than in the past, some investors argue that the group's growth rate no longer justifies its price premium. Even some tech leaders openly acknowledge those days are over. H-P ( HPQ) CEO Carly Fiorina has said the industry is likely to grow at a ratio of only one to two times GDP going forward. For H-P, that means growth of 7% to 9% this year is likely, compared to a compounded annual sales growth rate of 13.2% between 1992 and 2002. The leading trade group for the chip industry has said annual growth rates of 8% to 10% will be the norm going forward, compared to historic growth rates of around 15% or 16%. The outlook for slower gains is a painful come-down for an industry that's grown at 4.4 times the rate of U.S. GDP over the past three decades. Between 1971 and 2001, information-processing equipment and software grew at a compound annual rate of 13.6% a year, based on figures reported by the government's Bureau of Economic Analysis. The sector surged at an even faster clip in the '90s, at 14.4% a year. Meanwhile, GDP crawled along at a humble 3.1%. But assuming technology companies can no longer grow as fast as they used to, the logical takeaway is that investors shouldn't pay as high a multiple for stocks as they have over the past couple of decades. While software and services claim decent growth prospects, hardware and semi stocks, struggling with overcapacity and weak demand, are especially vulnerable to the downside.