After a much longer-than-expected delay,\u00a0double data rate, second generation (DDR2) has finally taken over as the most popular memory chip used in PCs.The crossover to DDR2 from the previous mainstream chip,\u00a0double data rate, 400MHz (DDR-400) took place this week on both the spot DRAM market and the contract market, industry researcher DRAMeXchange Technology said Wednesday.It\u2019s been a long time coming. The chips entered the market far later than expected, mainly due to heat problems. In fact, DDR-400, which has reigned as industry leader for the past few years, was supposed to be a stopgap chip with such a short life span that some companies hadn\u2019t even planned to support it with a chipset.But when DDR-400 showed up on Intel\u2019s product road map in late 2002, component makers began to move forward on DDR-400, and put off developing compatible parts for DDR2. Intel microprocessors power around 80 percent of all PCs, making an Intel stamp of approval vital to computer industry parts makers. Advanced Micro Devices (AMD) helped further put off demand for DDR2 this year. The company waited until the middle of the year to launch its first desktop and laptop processors that support DDR2 because it didn\u2019t think initial versions of the chip added substantial performance benefits to AMD processor-based systems, yet commanded a higher price.The first DDR2 chips ran at 400MHz and then 533MHz, but AMD waited until DDR2 chips running at 667MHz reached mass production levels, which lowered price and ensured a plentiful supply.Currently, a wide range of Intel and AMD systems support DDR2.DRAMeXchange noted Wednesday that prices may become an issue again for DDR2. Prices for the chips rose 8.8 percent last week, compared to the previous week, the company said, due to strong demand for PCs. The market researcher expects prices to remain strong throughout September, the traditional time when back-to-school PC buying increases buying activity in the DRAM market.-Dan Nystedt, IDG News Service (Taipei Bureau)Related Link:\n\nSamsung Shrinks 1-Gigabit DDR2 ChipsCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.