RxTx measures the data transfer bandwidth between your computer and multiple servers. It works with Dial-Up, Cable or DSL connections.

Bandwidth is measured by downloading one or more HTTP files and averaging the received data rates. You can specify a number of Internet addresses (or files) as they appear on your browser Address bar. The download speed is lower for binary files than for text (ASCI) files so you should choose both binary (.jpg, .gif, .exe, .zip) and text (.html, .asp, .txt) files for test.

Note that when you have your modem compression enabled and download the main HTML file of a Web page you'll get the highest bandwidth for that particular site. This is because the file is ASCI and also you get the server's attention. As a general rule, the bandwidth for binary files from the same site will be 50% lower.

In addition, RxTx displays in real time instantaneous and average data rates. The data rates are shown in Kbps (Kilo bites/second) or KB/s (Kilo Bytes/second).