The difference between the X86\x64\ia64

Source: Internet
Author: User

These days when you do MDT, you will always encounter x86\x64\ia64 these several folders. The first two are common, and are often encountered since the Win7 system appears. So I guess IA64 should also be some kind of architecture or version of the CPU. Now to the three made a summary.

x86 or 80x86 is the general term of a microprocessor architecture that Intel first developed and manufactured. The older processor names in this series are represented numerically and end with "86", including Intel 8086, 80186, 80286, 80386, and 80486, so the architecture is called "x86". The x86 architecture was first seen in the Intel 8086 Central processing Unit, launched in 1978, developed from the Intel 8008 processor, and 8008 developed from Intel 4004. 8086 was selected for IBM PCs three years later, X86 became the standard platform for personal computers and became the most successful CPU architecture in history, such as Pentium, Athlon. Now, Intel calls x86-32 the IA-32, the full name of "Intel architecture, 32-bit."

The birth of x86-64 architecture is of contemporary significance. At that time, processor development encountered a bottleneck, memory addressing space due to 32-bit CPU limit to the maximum of about 4G. AMD actively extends 32-bit x86 (or IA-32) to 64-bit. It appears with a schema called AMD64 (also known as x86-64 before renaming), and the first product based on this technology is the single core Opteron and Athlon 64 processor family. As AMD's 64-bit processor product line first enters the market and Microsoft is unwilling to develop two different 64-bit operating systems for Intel and AMD, Intel is forced to adopt the AMD64 instruction set and add some new additions to their own products, Named the EM64T architecture (apparently they did not want to admit that the instruction set was from its main opponent), EM64T was officially renamed Intel 64 by Intel. The two are collectively known as x86-64 or x64, creating the 64-digit era of x86.

In fact, IA64 's history is earlier than x86-64, initially by Intel and Hewlett-Packard jointly launched in 1990. Since IA64 is not compatible with 32-bit, it has not been taken seriously. Then Intel ia64 out the Itanium series of server CPUs for the ever-expanding computing needs. IA64 is a brand new system that has no similarity to the x86 architecture and should not be confused with x86-64 or x64. Based on the IA64 processor architecture, the server has 64-bit computing power, 64-bit addressing space and 64-bit data path, which breaks through many limitations of the traditional IA32 architecture, and obtains a breakthrough in data processing capability, system stability, security, usability and manageability. It is another milestone in the High-performance computing world since Intel launched its 32-bit microprocessor.

Both the x64 and IA64 processors are capable of running 64-bit operating systems and applications, but the difference is that the x64 architecture is based on x86 and is designed to allow x86 architecture CPUs to be compatible with 64-bit computing. The x64 architecture is designed to extend the current x86 instruction set in a straightforward and straightforward way. This approach is very similar to the original 16-bit expansion to 32-bit scenarios. The advantage is that the user can choose x86 platform or x64 platform with high compatibility. The IA64 is a native 64-bit compute processor and is incompatible with the x86 directive. If you want to execute the x86 directive requires hardware virtualization support, and inefficient. The advantage is that the IA64 architecture system will have 64-bit memory addressing capabilities to support a larger memory addressing space. And because of the architectural changes, performance is higher and stronger than the x64 64-bit compatibility mode. Therefore, the IA64 operating system is also relatively rare, because only in the Intel Itanium® series processors and AMD part of the server processor operation, so the mainstream market is not common. Also, these IA64 schema processors are not able to use the x64 operating system. The x64 processor is free to choose x86 or x64 operating systems.

Speed is not the only consideration in comparison between 32-bit systems and 64-bit systems. Or because of changes in numbers, it is simply assumed that 64-bit CPU performance is twice times the size of a 32-bit CPU. The actual 64-bit applications at this stage are not many, and even so, many are simply because their 32-bit versions cannot run on 64-bit operating systems. Without really doing 64-bit optimization programs, performance does not lead to too much ascension. On the contrary, in 32-bit applications, running 32-bit CPU performance is even stronger. On the other hand, because 32-bit Windows systems support only 3.25G of memory, 64-bit Windows systems can support 128G of memory maximum. Therefore, when the computer memory is greater than 4G, it is necessary to decisively use the 64-bit system.

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