Applications to evaluate Internet quality-of-service and increase network security are essential to maintaining reliability and high performance in computer networks. These applications typically use very accurate, but high cost, hardware measurement systems. Alternate, less expensive software based systems are often impractical for use with analysis applications because they reduce the number and accuracy of measurements using a technique called interrupt coalescence, which can be viewed as a form of sampling. The goal of this paper is to optimize the way interrupt coalescence groups packets into measurements so as to retain as much of the packet timing information as possible. Our optimized solution produces estimates of timing distributions much closer to those obtained using hardware based systems. Further we show that for a real Internet analysis application, periodic signal detection, using measurements generated with our method improved detection times by at least 36%.