A central processing unit (CPU) is to a computer what a brain is to a human body. It controls the rest of the parts by sending various signals. The 'to do' list of this electronic machine is called instructions. The CPU reads these instructions and carries out the tasks accordingly, one at a time. A computer program is a list of instructions a CPU can read. A CPU performs basic arithmetical and logical tasks and input/output operations.
The physical size of a CPU has reduced dramatically over the years with the invention of the microprocessor. Now a single silicon chip can even contain a CPU. The speed of a CPU is measured in hertz. One gigahertz (1 GHz) is equal to one billion hertz. Leading manufacturers of CPUs are Advanced Micro Devices (AMD) and Intel. Others manufacturers exist, but usage is much more limited.
There are a lot of buying considerations when it comes to CPUs. Preliminary knowledge of CPUs or processors is necessary before attempting to make a buying decision. CPUs can be acquired from eBay, which usually features an impressive collection of CPUs in a number of variations.
About Processor Terminologies
The two major components of a typical CPU are the arithmetic logic unit (ALU) and the control unit (CU). The former performs the arithmetic and logical operations, while the latter extracts instructions from the memory and decodes and executes them. The CU can also call ALU when required. The operation of a typical CPU revolves around a 'fetch, decode, execute, and writeback' cycle that repeats after every instruction cycle.
In multiprocessing, more than one CPU is used by a single computer. A multi-core processor is a form of microprocessor and contains multiple CPUs on a single chip. Microprocessors of today are integrated circuits (ICs) with hundreds of connecting pins in less than 4-centimetre square packages.
Not all systems have central processing units. There is no central element or brain in array processors or vector processors. They have multiple parallel computing elements instead. An interconnected and distributed set of processors is used in the distributed computing model for solving the various computational problems.
Important Considerations for Buying a CPU
With so many options for component configurations, buying a CPU has become a daunting task. With these limitless possibilities, there are also several buying considerations to keep in mind before making a decision. The many considerations include the number of cores in a CPU, the speed of the CPU, and thermal design power. The choice of the right CPU depends mainly on the intended use and the budget one is willing to allocate for this purchase. For day to day tasks like emailing, web browsing, and document editing, the lower-end options suffice, while for gaming, video editing, multi-tasking, and other similar tasks, higher-end CPUs are obviously the better option.
CPU Clock Speed
How quickly information can be processed is a function of clock speed. Depending on the intended use, a buyer may select a CPU clock speed that generally ranges from 1 GHz to 3.6 Hz and even beyond. If you are planning to perform modest tasks that do not require a lot of system resources, a 1 GHz processor, for example, is sufficient. For high-end users, however, greater clock speeds are required for carrying out tasks properly without any lags or hangs during the execution.
Thread and Core Selection
The number of cores is also an important buying consideration. With the advancement in technology, multiple cores can be found in a CPU. At the moment, the number of cores in processors ranges between one and eight. For low-end users, this is not that important, but for high-end users, it is one of the most critical considerations. Generally, the greater the number of cores, the greater the number of processes that can be completed simultaneously. Similarly, the greater the number of threads, the greater the number of concurrent tasks that can be completed per processor unit. A single or dual-core processor is more than enough for running simple Web and PC applications, but a quad-core or higher version is recommended for gaming and multimedia processing.
Thermal Design Power
Thermal design power (TDP) is also an important consideration and has to do with the maximum temperature level the processor can reach without damaging the CPU. The higher the value of TDP, the better. Higher thermal design power means that a CPU can manage more output without causing heat damage to the core.
32-Bit vs. 64-Bit CPU
The two main types of CPU structures are 32-bit and 64-bit. 64-bit processors are the most recent versions and feature increased capability for handling various processes and can process more instructions at the same time. Another key difference is the memory that can be handled by each of the CPUs. A 32-bit processor can only handle 4 GB of RAM, unlike a 64-bit processor, which has the capacity to handle as much as 192 GB of RAM. The memory that can be handled by a processor is not solely dependent on the processor speed. The operating system also plays a part. For example, for a 64-bit processor, Windows 7 Basic OS can only handle 8 GB of memory, while Windows 7 Ultimate can handle 192 GB.
The optimal amount of RAM on a 32-bit processor is between 1.5 GB to 2.5 GB, indicating that having 4 GB of RAM does not mean the system performs faster. Generally speaking, a 64-bit processor outperforms a 32-bit processor in every way.
Front Side Bus
The point of contact between the CPU and the motherboard is called front side bus or FSB. If this connection is fast, the information can be transferred more quickly. The units of measuring the transfer speeds are usually megahertz and gigahertz and typically range between 533 MHz and 1600 MHz.
Nanometres and Number of Transistors
The number of transistors that fit in a CPU can be directly estimated from the number of nanometres. A 65-nm processor, for example, features more transistors than a 45-nm transistor. The greater the number of transistors in a CPU, the smaller the space required for their packaging.
For better performance, every CPU manufacturer offers its own technologies. Intel, for example, offers Turbo Boost for better information distribution over each processor core. Other technologies include AMD CoolCore, Intel 64, and Virtualisation, among others. A buyer should go through the specifications to determine which technology is present and what it offers.
Compatibility of the various components a computer is made up of is an essential, inevitable consideration. First and foremost, the compatibility of the motherboard CPU socket should be determined. There are different types of CPU sockets, and the manufacturer's documentation should be consulted for identifying the specific CPU socket on your motherboard. The type of socket immediately shortlists the number of options for your computer.
Compatibility of the main system memory or RAM with the motherboard is also a non-negotiable consideration. Before placing an order, be sure that the RAM, motherboard, and processor are compatible with one another.
Buying CPUs on eBay
Enter search terms into the search bar on the eBay homepage to begin the search for a CPU or accessories. This is the quickest and easiest way of getting down to the right products in no time. Considering the endless possibilities, there may be many possible search terms, such as CPU, central processing unit, processors, 32-bit CPU, 64-bit CPU, et cetera. You can also filter out the results based on your personal preferences by simple selection of various given options. For some queries, eBay also suggests some related searches that often facilitate the purchasing process.
To look for a CPU in your neighbourhood in order to avoid the delivery charges, simply enter your postcode on the results page to view local search results. If you are able to find the desired processor or other accessories in your area, you can pick up the order at a time of your convenience as soon as the transaction is complete. It is highly recommended that you go through the feedback and reviews for a seller before committing to a purchase.
A central processing unit, or CPU, is the brain of a computer and, as such, is the most prominent and critical component. The to-do list of a CPU is termed as instructions, and the processing of these instructions determines how efficiently and quickly a computer operates. Most instructions are received in the form of a computer program. A CPU carries out basic arithmetical and logical tasks, as well as input/output operations. The arithmetic logic unit (ALU) and the control unit (CU) are the two primary components of a typical CPU. In multiprocessing, several CPUs are used simultaneously by a computer. Multiple CPUs are present on a single chip in multi-core processors.
A buyer should address several buying considerations before purchasing a CPU on eBay. These considerations include clock speed, core selection, CPU structure, and compatibility. eBay features a large collection of CPUs with a number of specs, including processor type, processor speed, and front bus speed, to serve a wide range of needs.