The main aim to design a processor to increase the clock speeds of processor whether it is RISC or SISC processor.In the view of these facts,dual-core processors is introduced in 2005.
A Dual- core processor is exactly what it sounds like. It is two processor cores integrated on one physical chip. Dual-core refers to a CPU that includes two complete execution cores per physical processor. It combines two processors and their caches and cache controllers onto a single integrated circuit (silicon chip).
Dual-core processors are developed for multitasking environments because there are two complete execution cores instead of one.Each of the core with an independent interface to the frontside bus. Since each core has its own cache, the operating system has sufficient resources to handle most complex tasks in parallel.
Multi-core is of an expansion to dual-core technology and allows for more than two separate processors.
The benefit of having multiple processors is the system can handle more than one thread. Each processor can handle a separate stream of data. This highly increases the performance of a system that is running concurrent applications such as a server.
All of the major current operating systems have multithreading capability. But you must have application software that support multithreading.Any speed benefits depends on the operating system that being able to separate applications between the processors.
We know that higher the clock cycle,faster the processor.Most of the early dual-core processors are going to be running at lower clock speeds compared to single core processors. The reason behind that a dual-core processor with each running at 1GHz should be equivalent to a single processor running at 2GBz. It doesn’t work in practice when the applications are not written to take advantage of the multiple processors.Until the software is written this way, unthreaded applications will run faster on a single processor than a dual-core CPU.
Advantage of Dual-core Technology
Dual-core processors support two complete execution cores instead of one, each with an independent interface .Since each core has its own cache, the operating system has sufficient resources to handle complex tasks in parallel, which is implementation of multitasking.
Optimization for the dual-core processor requires both the operating system and applications running on the computer to support a this technology .This level of technology is known as thread-level parallelism i.e.multiple threads running simultaneously.
Today ,Windows XP and hundreds of applications already support multithread technology. Now these days,dual-core technology becomes more common in homes and the workplace.
The microprocessor, (or CPU), is the brain of the computer. We can say that the heart of all personal computers and most workstations sits.The first microprocessors used a word size of only 4 bits, so that the transistors of its logic circuits would fit onto a single part. One or more microprocessors typically serve as the processing elements of a computer system.The first Microprocessors made possible in the mid-1970s. Before that, CPUs were typically made from small-scale integrated circuits containing the equivalent of only a few transistors.Now,it has become the most prevalent implementation of the CPU, almost completely replacing all other forms. In the world of personal computers, the terms microprocessor and CPU are used interchangeably . Microprocessors control almost all the logic of digital devices.
Three basic characteristics differentiate microprocessors:
- Instruction set : The set of instructions that the microprocessor can execute.
- bandwidth : The number of bits processed in a single instruction.
- clock speed :The clock speed determines how many instructions per second the processor can execute in in megahertz (MHz).
The higher the value of thdese three basic characteristics , the more powerful the CPU,for example:32-bit microprocessor that runs at 50MHz is more powerful than a 16-bit microprocessor that runs at 25MHz.
There are two type microprocessors :
1.RISC (reduced instruction set computer)
2.CISC (complex instruction set computer).
RISC : As per its name,it is designed to perform a smaller number of types of computer instructions so that it can operate at a higher speed(MIPS) . Since each instruction type that a computer must perform requires additional transistors and circuitry, a larger list or set of computer instructions tends to make the microprocessor more complicated and slower in operation.The PowerPC microprocessor, used in IBM’s RISC System/6000 workstation and Macintosh computers, is a RISC microprocessor.
CISC : As per its name,it is designed to perform with a full set of computer instructions that were intended to provide needed capabilities in the most efficient way.Intel’s Pentium microprocessors are CISC microprocessors. RISC takes each of the longer, more complex instructions from a CISC design and reduces it to multiple instructions that are shorter and faster to process.