Processing and Memory

Understanding PART Computer Hardware I COPYRIGHTED MATERIAL cc01.indd01.indd 1 99/21/11/21/11 66:40:45:40:45 PPMM cc01.indd01.indd 2 99/21/11/21/11 66:40:46:40:46 PPMM Chapter Processing 1 and Memory COMPTIA FUNDAMENTALS OF TECHNOLOGY (UK) IT FUNDAMENTALS (USA) OBJECTIVES COVERED IN THIS CHAPTER: 1.1 Identify basic IT vocabulary ■ Processor speed/cores ■ RAM cc01.indd01.indd 3 99/21/11/21/11 66:40:47:40:47 PPMM Every computer, whether it’s a high-speed supercomputer at a research facility or a hand-held game for children, has a processor—the component that performs math calculations. Every computer also has some type of random access memory (RAM), which is used for temporary data storage as data moves into and out of the processor. In this chapter, you’ll review the basics of processors and RAM. Having this information will help you evaluate these components in the computers you buy, use, and maintain. Processors Every computing device has a central processing unit (CPU), more commonly known as a processor (or microprocessor). Processors are a part of mobile phones, gaming consoles, digital music players, and everything from automobiles to washing machines. Some computers even have multiple processors that share the computing load for faster performance. Processors are integrated circuits containing millions of electronic components called transistors. Transistors are an important component in any electronic device, including a computer. Transistors are electrical gates that let power through or don’t depending on their current state. They’re the basis of binary processing—that is, processing based on things being in one of two states: on or off, 1 or 0. At its most basic level, a processor’s job is to do math. It accepts numbers as input, performs calculations on them, and delivers other numbers as output. It’s mostly oblivious to the signifi cance of those numbers; it just runs the instructions it has been given. It’s a common misconception that the processor is the brain of the computer—it’s not nearly as sophisticated as a human brain. It just does what it’s told, like a hand-held calculator, but at incredibly high speed. The brains of the operation would more accurately be the operating system (OS), which feeds the numbers to the processor and uses the results. Different processors have different instruction sets—that is, different math calculations they can perform. The advanced processors in personal computers (PCs) have very large and complex instruction sets; the simple processors in items like appliances have fewer instruction sets. The OS must be written with the processor’s instruction set in mind so it can send the right codes to activate the desired instructions. Processors also vary in the number of bits they can accept and process as input. A bit is a binary digit, either 0 or 1. The more bits a processor can accept simultaneously, the faster it can work through the backlog of data to be processed. The earliest PCs had 8-bit or 16-bit processors; today, PCs have 32-bit or 64-bit processors. The higher the number of bits, the larger the word size the processor can accept. Word size refers to the amount of data that can simultaneously enter the processor in one operation. cc01.indd01.indd 4 99/21/11/21/11 66:40:47:40:47 PPMM Processors 5 RISC Reduced instruction set computing (RISC) is based on the principle that having a simple instruction set for a processor improves performance. The logic is that the more you can ask of a complex processor, the slower it becomes. Thus a processor that is capable of a smaller set of tasks can complete them more quickly. The Advanced RISC Machine (ARM) is a popular processor found in many mobile computing devices, including cell phones and hand-held game machines. In contrast, most personal computer processors are considered complex instruction set computing (CISC), having a comparatively large instruction set for greater fl exibility. Processors work only with binary digits, so the OS translates all numbers to the binary numbering system in order to send them for processing. Humans most commonly use the decimal numbering system (digits 0 through 9). Computers typically use hexadecimal numbering (16 digits, 0 through 9 plus A through F) or binary numbering (2 digits, 0 and 1). Binary is used when interacting with the processor, and hexadecimal is used when the OS refers to memory addresses. Exercise 1.1 demonstrates how to convert between binary and other numbering systems. EXERCISE 1.1 Convert Between Binary and Other Numbering Systems 1. In Windows 7, open the Calculator application. 2. Choose View Programmer to switch to Programmer view, as shown here. Notice that the Dec radio button is selected, indicating decimal numbering. cc01.indd01.indd 5 99/21/11/21/11 66:40:48:40:48 PPMM 6 Chapter 1 ■ Processing and Memory EXERCISE 1.1 (continued) 3. Enter the number 335. 4. Click the Bin radio button. The number is converted to binary (101001111). Notice that all the number keys are disabled except 1 and 0. 5. Click the Hex radio button. The number is converted to hexadecimal (14F). Notice that all the number keys are active again, as are the A through F keys. 6. Click the Dec radio button again to return to decimal numbering. 7. Experiment on your own with more numbers. Close the Calculator app when you’re fi nished. Processor Brands A variety of manufacturers produce processors that serve inside appliances and other non- computer devices. However, for personal computer processors, market competition has virtually eliminated all but two manufacturers, Intel and AMD. Apple Macintosh computers used Motorola processors for many years but switched to Intel processors in mid-2006. Intel Processors Intel is the most popular brand of processors for personal computers. Since the company’s founding in 1968, it has manufactured more than 50 different processors, plus graphics cards, motherboards, and various computer peripheral devices. The original IBM PC and PC-XT computers ran on Intel processors (the 8088 and 8086, respectively). Later IBM models also used Intel processors, such as the PS/2 that used the 16-bit 80286 processor. In 1993, Intel released the original Pentium processor, the fi rst commercially viable 32-bit CPU. It was followed by the Pentium 2 in 1997, the Pentium 3 in 1999, and the Pentium 4 in 2000. Intel’s current offerings include a 64-bit line called Intel Core, which includes the Core i3, Core i5, and Core i7. The Core i3 is an entry-level CPU, the Core i5 is midrange, and the Core i7 is a high-end product. As you might expect from the word core in the name, each of these is a multicore processor (containing from two to six cores, depending on the model, each of which functions as a processor in its own right). Within Intel’s Core lineup are many different versions of the i3, i5, and i7, for both desktop and laptop use, each with a different codename and combination of number of cores, L3 cache size, and socket type. For example, the brand name Core i3-5xx (where each x represents a digit), codenamed Clarkdale, has two cores and a 4 MB L3 cache and fi ts in an LGA 1156 socket. Some of the other codenames include Arrandale, Lynnfi eld, Gulftown and, the most recent of these, Sandy Bridge. cc01.indd01.indd 6 99/21/11/21/11 66:40:48:40:48 PPMM Processors 7 AMD Processors Advanced Micro Devices (AMD) has been the strongest competitor to Intel in the PC processor market since the 1990s. AMD processors have historically been less expensive than Intel’s, while offering roughly equivalent performance. Because AMD processors use a different instruction set than Intel’s, they require motherboards specially designed for them. The motherboard is the large circuit board inside a PC to which everything else connects. AMD’s early CPU offerings included the K5, K6, K7, K8, and K9 processors, each of which competed directly with an Intel processor. AMD’s current lineup includes the Phenom II, Athlon II, and Turion II lines. Processor Sockets Processors require the correct type of socket in the motherboard in which you’re installing them. When buying a motherboard, make sure the processor socket is appropriate for the CPU you plan to use. Sockets use various code names and numbering. The numbering is often based on the number of pins, or contacts, on the chip. For example, the LGA 1356 contains 1,356 pins. In earlier times, a pin grid array (PGA) was the preferred style of processor socket. It consisted of a grid of tiny holes into which the tiny pins on the back of a CPU chip were secured. Figure 1.1 shows a PGA socket in a motherboard circa 2005. FIGURE 1.1 Pin grid array (PGA) was a common type of processor socket until a few years ago. Photo credit: Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. User:Berkut cc01.indd01.indd 7 99/21/11/21/11 66:40:49:40:49 PPMM 8 Chapter 1 ■ Processing and Memory However, in recent years, this design has been replaced by land grid array (LGA), a style that has no pins on the chip. Figure 1.2 shows an example of an LGA socket. In place of the pins are tiny pads of bare gold-plated copper that touch corresponding pins on the socket. The main advantage of LGA is size; the pads can be much smaller than a socketed pin, so the CPU can contain more connection lines to the motherboard without the size of the CPU socket becoming very large.

Load more