Yale

There are many situations when you have multiple Internet-connected applications running on your computer, and it's always a good idea to keep an eye on their resource consumption to ensure that you know which of them can slow down your system.
One of the tools that you can use in such cases is Yale, a small utility designed specifically for displaying info on the network usage of running software.

A simple interface

Yale appears to have been built with simplicity in mind, and this is exactly what you will notice when opening it for the first time. It does, however, allow you to change its color and what information it shows.
The app will place an icon in the System Tray and will show a graph of resource usage for different applications on the lower right side of the desktop, but you can easily move it to any region of the screen.

Monitor multiple network adapters

With this tool, you can keep an eye on the usage of multiple network adapters. Clicking on each of them will expand the view, allowing you to see additional details on resource consumption.
The tool provides you with info on the bandwidth that each application consumes, as well as on the network protocol and DNS server. There's also a 'port-numbers.txt' file that you can place into the same directory as 'Yale.exe' in order to expand the set of known protocols.

View CPU and disk usage statistics

In addition to resource usage for each network adapter on your machine, Yale can offer details on how much of the CPU and hard disk are put to work.
One thing that you should keep in mind when using this tool, however, is that it will parse each transferred package when expanding the view for a network adapter, which could slow down your data transfer speeds.
All in all, even if it has been designed as a very simple network resource monitoring tool, Yale does its job very well, and can easily prove a useful utility for your computer at all times.