To understand the impact of page file size, it is useful to outline how data is measured. File size is calculate in bytes, sets of eight bits. 1024 bytes is a kilobyte is a kilobyte, or 1K. Bandwidth is measured in bits per second, so, allowing for a few extra bits that have to be transmitted for technical reasons, the maximum number of kilobyte received per second will be around a tenth of the modem’s Kbits/sec rating. Most modem still in use are 56 Kbits/sec, so they’ll pull down no more than about 5K per second. In practice, the norm is between 38K and 44L, depending on the quality of the telephone line connection.