In a conversation with the network administator, I mentioned that my machine was a dual-core. He told me it was not. I brought up the task manager, went to the perfomance tab, and showed him that there are two separate CPU usage graphs. I have a quad-core machine at home and it has four graphs. He told there were two graphs on this particular machine because of hyper-threading. I used to have a hyper-thread pentium 4 processor back in the day, but I never fully understood what it meant. So what is the difference between hyper threading and dual-core? And how do you tell which one you have?