Linux software installation FAQ x86 or x64

Linux software installation FAQ x86 or x64

Civilian information:

X64 indicates that the CPU is a 64-bit version. X86 means that the CPU is a 32-bit version. If your CPU is 64-bit. You can install 64-bit or 32-bit. In turn, you can only install 32-bit.

RedHat Linux
Getconf long_bit

32 is returned, and 64 is returned.

Expert Information:

X86 is short for Intel processor-based systems. X has nothing to do with the processor. It is a simple wildcard definition for all * 86 systems. It is an Intel general computer series number and also identifies a set of general computer commands, since Intel's CPU numbers were all numbers such as 8086, 80286 in the early days, since the entire series of CPUs were compatible with commands, x86 was used to identify the current Pentium, P2, the P4 and sai Yang series support x86 command systems, so they all belong to the x86 family.

Here, the 64-bit technology is relative to 32-bit. This number of digits indicates that the data width of cpu gprs (general-purpose registers, general-purpose registers) is 64-bit, the 64-bit instruction set is the command to run 64-bit data, that is, the processor can run 64-bit data at a time. 64-bit processors are not available now. 64-bit processors have been available for a long time in high-end CPU (Reduced Instruction Set computers, for example, sun's ultrasparc III, IBM's power5, and HP's Alpha.

64bit computing has two main advantages: it can perform integer operations in a larger range; it can support larger memory. We cannot simply think that 64-bit processor performance is twice the performance of 32-bit processor because of Digital changes. In fact, in 32-bit applications, the performance of 32-bit processors is even stronger. Even 64-bit processors have higher performance in 32-bit applications. Therefore, we need to recognize the advantages of the 64-bit processor, but do not believe that 64bit.

To implement a true 64-bit computing, a 64-bit processor is not enough. A 64-bit operating system and 64-bit application software are required, without any of these elements, 64-bit computing cannot be implemented. For 64-bit processors, Intel and AMD both have released multiple series of 64-bit processors with multiple specifications. In terms of operating systems and application software, the current situation is not optimistic. Because Windows XP x64 is the only 64-bit operating system suitable for personal use, Windows XP x64 is also a transitional 64-bit operating system, after Windows Vista is released, it will be phased out, and Windows XP x64 itself is not perfect and easy to use. An obvious example is that drivers of various hardware devices are not complete, in addition, the 64-bit application software is basically not available. It is true that hardware and software vendors are reluctant to write drivers and applications for a transitional operating system. So if you want to implement a true 64-bit computing, you may have to wait until Windows Vista is popularized for a while.

Currently, the 64-bit CPU technology mainly includes amd amd64-bit technology, Intel em64t technology, and Intel IA-64 technology. Among them, IA-64 is independently developed by Intel, not compatible with the current traditional 32-bit computer, only for itanium (anteng) and subsequent products itanium 2, general users will not involve, therefore, we will only give a brief introduction to amd64-Bit Technology and Intel's em64t technology.

Amd64-Bit Technology

Amd64 bit technology is added to the original 32-bit x86 Instruction Set Based on the X86-64 extended 64-bit x86 instruction set, so that the chip is compatible with the original 32-bit x86 software in hardware, it also supports 64-bit X86-64 extension, making this chip a real 64-bit x86 chip. This is a true 64-bit standard with a X86-64 capable of 64-bit addressing.

Several new sets of CPU registers added to the X86-64 provide faster execution efficiency. Registers are used internally by the CPU to create and store the CPU operation results and other operation results. The Standard 32-bit X86 architecture includes eight General registers (GPR), and AMD adds eight more groups (X86-64) in the R8-R9 to increase the number of registers to 16 groups. X86-64 registers default bit 64-bit. Also added 8 128-bit XMM registers (also called SSE registers, XMM8-XMM15), which will provide more space for single-instruction multi-data stream technology (SIMD) operations, these 128-bit registers provide 128-bit dual-precision processing in vector and scalar computing mode, providing hardware basis for 3D modeling, vector analysis, and VR implementation. By providing more registers, CPUs produced according to X86-64 standards can process data more effectively and transmit more information in a clock cycle.

Em64t Technology

Intel officially defines em64t as follows: em64t stands for extended memory 64 technology, that is, extended 64 bit memory technology. Em64t is an extension of the Intel IA-32 architecture, namely, IA-32e (Intel Architectur-32 extension ). With the em64t technology attached, the IA-32 processor allows software to take advantage of more memory address space while being compatible with IA-32 software, and allows the software to write 32 bit linear addresses. Em64t especially emphasizes the compatibility between 32 bit and 64 bit. Intel added 8 64-bit GPRS (R8-R15) for the new core, and expanded all the original GRPS to 64-bit, as described above, which can improve the integer computing capability. 8 128bit SSE registers (XMM8-XMM15) were added to enhance multimedia performance, including support for SSE, sse2, and sse3.

Intel designed two models for processors supporting em64t technology: Legacy IA-32 mode and IA-32 mode ). In a processor supporting em64t technology, there is a part called extended feature enable register, ia32_efer. bit10 controls whether em64t is activated. Bit10 is called IA-32e mode active or long mode active ). When LMA = 0, the processor runs in the traditional IA-32 mode as a standard 32-bit (ia32) processor; When LMA = 1, em64t is activated, the processor runs in IA-32e extended mode.

Currently, amd supports 64-bit CPU, including the athlon 64 series, athlon FX series, and opteron series. Intel's 64-bit CPU supports the Nocona core Xeon series, the Pentium 4 6 series using the Prescott 2 m core, and the P4 EE series using the Prescott 2 m core.