Problems to be considered in the hottest multi-cor

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Problems to be considered in multi-core design

why adopt multi-core? If you design a processor twice the original size, the performance will not increase to twice the original size, and the performance will only increase by the square root. Therefore, doubling the size will not bring about the same order of performance growth, but only about 1.4 times the original performance, that is, an increase of 40%. This is called Pollack's Law (defined by Intel engineer Fred Pollack) and has been proved in single core systems. Chip manufacturers try to use multiple cores to improve the coefficient of performance and speed improvement

but designing a multi-core system faces some new challenges

communication gap

communication between cores may be the most critical issue, because it will play a vital role in some systems. There is no need for special measurement. The increase of general traffic and the core national entrepreneurship just postpone the number of employment crises. N is a quadratic equation (n+1) *n/2. Therefore, the communication data volume of a four core system will increase tenfold compared with that of a single core system. A 16 core system is expected to increase to 136 times the original by 2025, and a 256 core system will increase by more than 32000 times! Therefore, a flexible communication system between cores is the most basic for the work of multi-core system

several solutions are to use central memory for buffering, but problems will occur when all processor cores communicate internally with memory. Generally, packet switching network or other architectures will be adopted

we can make an interesting analogy, assuming that this is a human organization. If the number of people increases, communication will become difficult, and even bring bottlenecks. If it is a small group of two or four people, communication is much easier. If the number of people is more than 20 or more, a more effective communication structure is needed, such as weekly meetings, technical groups, etc

practice shows that a group of 6 to 8 people is the most effective. Larger groups need reasonable structures and other forms of consultation and collaboration. The same is true in multi-core systems

human design factors

human design factors will also affect the architecture of multi-core systems. In 1990, I gave a technical lecture in Eindhoven, the Netherlands. I decomposed the design into modules one by one and the interconnection between modules. Similarly, the relationship between the number of connections and the number of modules is a quadratic equation

the method to solve complex problems is the ability to apply and summarize concepts. Here, some components are regarded as macro components

bottom up design, simple decomposition and construction of various components until the most basic composition - logic gates or operation units, for example, using hierarchical methods, complex quadratic equation problems can be simplified to linear problems

in designing a multi-core system, it is very important to complete the management of communication and design complexity, and to select the appropriate architecture, design ideas, tool applications, etc

balance of power consumption

reducing the power consumption and heat dissipation of multi-core systems is another major problem faced by engineers. Reducing power consumption can be achieved by limiting the operation of each core, which is called "voltage scaling" -- the frequency and supply voltage of each core can be optimized according to the task operation of each processing core

another factor to be considered is that it can be inferred from the process that if the elongation of materials processed in parallel exceeds 1000%, the number of strokes of 1000 or 1200mm can be selected. If there are few parallel operations, there is no advantage to use multi-core processing

multithreading is a method of processing parallel operations. Writing software in the communication processor is another method. These techniques are supported by special operations to maintain the accuracy and consistency of the system

Author: Cees Jan koomen, the vast majority of plastic processing enterprises are mainly domestic manufacturing equipment, and are former executives of Royal Philips. At present, they are committed to the investment and venture capital of many start-ups and the construction of the ecosystem in the Netherlands. (end)

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