Advanced Micro Devices gained 2.5 percentage points of the worldwide microprocessor market last quarter, iSuppli Corp said Tuesday, a much greater gain than the research group had estimated. Intel, AMD"s bigger rival, lost 2 percentage points of market share compared with the previous quarter in iSuppli"s final second-quarter microchip revenue market survey, compared with a July estimate of a 0.5 point gain. AMD"s revised estimated advance, up from iSuppli"s July estimate of 0.5 percent, gave it a 13.4 percent share of overall microprocessor revenue in the second quarter, while Intel had 78.8 percent, iSuppli said.