CPU = Central Processing Unit
To find out usage, start task manager, there's a graph showing total usage, the processes tab shows in realtime what each process is using.
I'll admit I'm unfamilliar with the bandwdith graphs in WinMX & what the colours mean.. I've rarely even glanced in years of running the program
1 MB would be 1,048,576 bytes 1 GB would be 1024 times that...