1 00:00:00,000 --> 00:00:06,800 We've gotten used to throwing around the term CPU core, the part of your processor that does the actual, you know, processing. 2 00:00:06,800 --> 00:00:11,800 We understand that more cores are usually better, especially for applications like video editing. 3 00:00:11,800 --> 00:00:16,300 But what exactly makes a core different from the rest of the CPU? 4 00:00:16,300 --> 00:00:22,000 And how exactly do they work? It's probably useful to first define what a core is not. 5 00:00:22,000 --> 00:00:29,600 Cores don't handle I.O. or input output from the rest of the system as there's a separate part of the CPU die that deals with that. 6 00:00:29,800 --> 00:00:37,300 Nor do they provide you with the graphics. That is the responsibility of an integrated GPU, which also sits on a different part of the die. 7 00:00:37,300 --> 00:00:42,400 So now let's look at what a core does do by talking about the different parts of a core. 8 00:00:42,400 --> 00:00:46,100 Let's start out with the ALU or Arithmetic Logic Unit. 9 00:00:46,100 --> 00:00:51,000 The ALU does exactly what it sounds like. It's the part of your computer that does the thinking. 10 00:00:51,000 --> 00:00:57,600 More specifically, it handles mathematical operations and also carries out logical operations such as comparing different values. 11 00:00:57,700 --> 00:01:00,900 Although this might make the ALU sound like a fancy calculator, 12 00:01:00,900 --> 00:01:08,400 the programming languages that enable everything you do on your computer rely on math and formal logic that the ALU can understand. 13 00:01:08,400 --> 00:01:12,500 Cores often also have a floating point unit, which is similar to an ALU, 14 00:01:12,500 --> 00:01:16,500 but deals with number sets that have their decimal points in different places. 15 00:01:16,500 --> 00:01:20,900 And you can learn more about what this means and why it's important in this video right up here. 16 00:01:20,900 --> 00:01:25,400 But how do the ALU and the FPU know what to work on? 17 00:01:25,400 --> 00:01:28,500 Well, data is fed to these units by registers. 18 00:01:28,500 --> 00:01:33,700 These are temporary holding places for whatever the CPU core has to process next. 19 00:01:33,700 --> 00:01:39,100 One type of register, called an input register, holds the data that the CPU needs to process, 20 00:01:39,100 --> 00:01:45,200 while another type of register, called an instruction register, tells the CPU what to do with that data. 21 00:01:45,200 --> 00:01:50,800 So if the system needs to multiply 6 and 3, it will place 6 and 3 into the input registers 22 00:01:50,800 --> 00:01:53,900 and a multiply instruction into the instruction register. 23 00:01:53,900 --> 00:01:57,300 The ALU will then figure out the product, 18 in this case, 24 00:01:57,300 --> 00:02:02,600 and send the result to yet another part of the core called an accumulator. 25 00:02:02,600 --> 00:02:05,900 The accumulator then sends the result to the cache, 26 00:02:05,900 --> 00:02:10,900 which is a small amount of extremely fast memory built into each core. 27 00:02:10,900 --> 00:02:17,400 This data can then be read by the program that requested it. And by the way, the cache sends data the other direction as well. 28 00:02:17,400 --> 00:02:23,700 Specifically, it holds the data and the instruction the CPU has to process and execute before that data enters the ALU. 29 00:02:23,700 --> 00:02:27,900 Now, at the beginning of all this, the data is initially fetched from your main system RAM, 30 00:02:27,900 --> 00:02:33,700 but having it in the cache before the cores need to process it makes your PC run much faster. 31 00:02:33,700 --> 00:02:38,900 Once the CPU core finishes working on one instruction, it of course has to move on to the next one. 32 00:02:38,900 --> 00:02:42,500 So another part of the core is called the instruction pointer. 33 00:02:42,500 --> 00:02:47,700 It contains the location and memory where the CPU should load the next instruction from. 34 00:02:47,700 --> 00:02:54,500 But what ties all of it together? To find the answer out, we actually have to go outside the cores themselves. 35 00:02:54,500 --> 00:02:59,700 The CPU features a memory management unit or MMU that's separate from the cores 36 00:02:59,700 --> 00:03:05,000 that directs the data that flows between RAM and the CPU cores, kind of like a traffic cop. 37 00:03:05,000 --> 00:03:10,600 And the CPU die also has a control unit that manages the cores by synchronizing their different parts 38 00:03:10,600 --> 00:03:18,300 so that they work together fluidly. To do so, the control unit uses a clock signal that runs at a specific clock rate. 39 00:03:18,300 --> 00:03:25,300 That same number you see on your CPU or computer's label given in gigahertz or billions of clock cycles per second. 40 00:03:25,300 --> 00:03:32,100 Fast enough to help you watch this video. So hopefully now you understand the difference between a CPU core and the other parts of your processor. 41 00:03:32,100 --> 00:03:39,300 And we know this was a very simplified high level overview of a very complicated device like a CPU. 42 00:03:39,300 --> 00:03:43,600 We don't exactly have time to get into a whole PhD dissertation here on Tech Quicky, 43 00:03:43,600 --> 00:03:48,600 but maybe you'll find one of those down in the comments. So thanks for watching guys, if you liked this video, hit like, hit subscribe, 44 00:03:48,600 --> 00:03:53,600 and hit us up in the comments with your suggestions for topics that we should cover in the future.