In this chapter you will learn how to: Describe different types of CPUs Explain RAM types and technologies Identify Motherboards Describe Power Supplies and Cases
A microprocessor, or central processing unit (CPU), handles most of the math processing in any kind of computing device A CPU beats at the heart of every Windows PC, but is also found in single-purpose computing devices, such as iPods and Xboxes Two companies make most of the CPUs found in today's devices: Intel and Advanced Micro Devices ( AMD)
CPUs plug into motherboards designed specifically for those CPUs A mother board is the part inside of a computer that everything else plugs into If you have an AMD CPU, you can only use it with a motherboard designed for AMD CPUs An Intel CPU requires a motherboard designed to run an Intel chip The CPU's job is to process information as quickly as possible The better the processor the more quickly it can perform tasks
The basic measurement of a CPU is its speed or how many tasks it can do in one clock cycle Completing one cycle per second is known as 1 hertz (Hz) Early CPUs measured speed in millions of cycles per second, or megahertz Mhz Today's CPUs run at billions of cycles per second, or gigahertz GHz
A CPU works directly with the motherboard to achieve the proper speed Motherboards run at a specific clock speed, measured in MHz. called the bus speed CPUs run at some multiple of that bus speed, such as lOx or 25x If the motherboard runs at 100MHz and the CPU has a 25x multiplier, the CPU runs at 2500 MHz (2.5Ghz)
First Intel Processor was the 4004 which had a clock speed of 740,000 Hz Intel 8088 CPU used in the first IBM PC had a clock speed of Hz, 4.7 Mhz Intel Pentium 4 CPU ultimately reached speeds of hz 3.95 Ghz
The absolute speed a CPU can be clocked is determined by the laws of physics In the year 2000 Intel theorized that the maximum speed a processor could run at was about 1Ghz They eventually were able to manufacture a Pentium IV that had a clock rate of just less than 3.95 Ghz
If the speed of a CPU is determined primarily by clock speed the Pentium IV would have been the fastest CPU Other manufacturing techniques are used to increase the speed of a processor Intel went from a 32 bit processor to a 64 bit processor, allowing twice as much data to be sent for each clock pulse
Early CPUs since the used a 32-bit architecture Meaning a CPU could could handle data 32 bits at a time Newer CPUs are capable of handling 64 bits making them twice as fast A 32-bit processing running at a clock rate of 2Ghz is considerably slower than a 64-bit processor running at the same speed Another advantage of slowing down the clock rate is that the CPU uses less power and creates less heat Microsoft newer operating systems are created to run as either 32 bit or 64 bit
Both Intel and AMD decided to combine two CPUs into a single chip creating a dual-core architecture. This architecture increases both processing capability and efficiency because each core can pick up the slack when the other core gets too busy, tasks can be split between each core Prior to dual-core CPUs, all CPUs were single core Modern CPU makers offer CPUs with two (dual- core), four (quad-core), six (hexa core), even eight cores (octa-core) on a single chip These are known collectively as multicore processors
CPUs have a preset list of commands they understand called the codebook or instruction set Programmers write applications in different computer languages that are translated into code understood by the CPU's instruction set The processor then works through the code and outputs commands to various parts of the computer
Different CPUs work with incoming commands and data differently CPUs with same clock speed won't necessarily process the same image in a complex application in the same amount of time Two CPUs might even reverse who wins when doing something simpler, like copying a huge file from one drive to another Older CPUs with a fast clock speed will stagger when compared to a CPU of today with a much slower clock speed due to the increase from 32 bit to 64 bit processing AMD processors once held the edge over Intel processors in simple efficiency, while Intel held the edge in speed Now Intel has joined the efficiency race in a big way and holds both the speed* and efficiency crowns, at a very steep price For a lot less money you can get an AMD processor that's nearly as good as a high end Intel processor
When the text was published, a quad-core Intel Core i7 processor running at 3.06 GHz costs about $600 at retail. A quad-core AMD Phenom II X4 CPU running at 3.4 GHz costs about $200 retail.
All running programs have to be in RAM, it's the only way the CPU can retrieve data fast enough to function properly CPU makers discovered (80386) that adding a little bit of super- fast RAM (Cache) directly onto the CPU could greatly speed up the whole computing process CPUs have several levels of cache, called level 1 (Ll ), level 2 (L2), and, on the highest-end processors, level 3 (L3) ◦ Ll is the smallest and fastest ◦ L2 is bigger but slower ◦ L3 is the biggest and slowest type of cache. ◦ All cache is considerably faster than system RAM. As a general rule with cache, bigger cache makes for a more efficient (and more expensive) CPU
One way to produce better/faster processors is to speed up the system clock However faster CPUs require more electricity and generate more heat Heat is the number one killer of electronics devices Huge power consumption is an issue with laptops and cell phones How do you increase speed without increasing power consumption? How do you increase speed without increasing power consumption?
CPU makers discovered while working on CPUs for portable computers that if you make the components of the CPU very tiny, you can get the same performance with less electricity Less electricity results in less heat If you improve the instruction set the CPU can perform better with even less electricity Modern CPUs have slower clock speeds than yesterday's high-end CPUs, use less electricity and produce less heat, they also outperform those earlier CPUs by adding cache
CPUs uses random access memory (RAM) to work with active programs An active program is a program that has been copied from mass storage into RAM RAM is measured primarily in terms of the amount of data that can be held at one time The more RAM your system has, the more tasks it can perform at once A typical stick of RAM, can hold 1 GB of data or programming Many hard drives, which are also measured in terms of capacity, can hold more than 500GB
The big difference between RAM and Hard Drives is volatility and speed RAM is volatile memory, which means that if the power goes out all the data in RAM disappears Ram is magnitudes times faster thnn a Hard drive Hard drives are nonvolatile, so the data on the hard drive stays there even without power RAM is considered Primary storage, Hard drives are considered Secondary storage
RAM also has a speed rating that describes how fast it can transfer data There are 3 speed technologies: DDR, DDR2, and DDR3, each is twice as fast as the technology that preceded it Double data rate (DDR) RAM can send or receive data twice for each clock tick on the motherboard A motherboard that runs at 100 MHz will need DDR RAM that runs at (at least) 200 MHz DDR2 & DDR3 RAM run at 4x or 8x the motherboard speed, respectively A motherboard that runs at 100 MHz would need DDR DDR3 motherboard at the same speed would need DDR3- 800
Motherboard Speed 100 MHz 133 MHz 166 MHz 200 MHz 100 MHz 133 MHz 166 MHz 200 MHz Speed Rating DDR2-400 DDR2-533 DDR2-667 DDR2-800 DDR3-800 DDR DDR DDR3-1600
RAM comes on small circuit boards called RAM sticks There are several different types of RAM sticks the two most common are called DIMMs and SODIMMs Typical desktop computers use DIMMs Portable computers and some desktops use the smaller SODIMMs. Portable computers and some desktops use the smaller SODIMMs.
You can't mix RAM stick types or technologies RAM sticks are keyed so that they only fit in the motherboard designed for that technology You can't install RAM that is too slow for the motherboard, it might fit, but the system will not boot RAM that's faster than the motherboard will simply slow down for the motherboard and work just fine DDR2 DDR3
Dual inline memory modules (DIMMs) have two rows of connectors at the bottom of the stick, one row on one side, the other row on reverse You'll find individual RAM chips on one or both sides of the stick Different technologies use slight variations in the number of pins or contacts, the main form factor is the same ~4” wide circuit board
Small outline DIMMs (SODIMMs) are about half the physical size of DIMMs, but they have similar capacities and perform just as well. SODIMMS are used in laptops
There is another type of memory used in systems referred to as ROM - Read Only Memory is used to store important data directly on the chip rather than storing it on the hard drive ROM typically contains instructions used by the operating system
Everything in a computer plugs directly or indirectly into the motherboard The motherboard has a lot of circuits and processing chips that have their own distinct jobs Motherboards have chips that control various components, such as keyboards, mice, monitors, etc Manufacturers create motherboards in many shapes and sizes referred to as form factors Most motherboards today offer built-in networking, sound, even have built-in video connections
All newer motherboards use a 24-pin connector called ATX for primary power. Plus they use a 4-pin P4 connector to help run more stably. 24 Pin power connector
Different cases offer solutions for different rooms and purposes A large office, could easily handle a full-size case with room inside for adding more things later A small, all-in-one computer might work much better for a dorm room with limited space The key thing to keep in mind when choosing a case is to match the form factor of the motherboard. A large motherboard, won't fit in a tiny case
Motherboards come in all sizes