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http://en.wikipedia.org/wiki/X86-64
有点长，改天翻译一下
“从这个意义上，P4的64位是伪64位。P4从生到死，从来就没有被设计成64位，它内部整数运算都是32位的”，这个说法貌似有点问题，摘选几段
AMD licensed its x86-64 design to Intel, where it is marketed under the name Intel 64 (formerly EM64T). AMD's design replaced earlier attempts by Intel to design its own x86-64 extensions which had been referred to as IA-32e
The last processors Intel manufactured which did not use AMD's x86-64 design were early versions of the desktop Pentium 4 "Prescott", introduced in February 2004, and mobile Intel Core introduced in January 2006.
“Intel 64 is Intel's implementation of x86-64. It is used in newer versions of Pentium 4, Pentium D, Pentium Extreme Edition, Celeron D, Xeon and Pentium Dual-Core processors, and in all versions of the Core 2 and Intel Core i7 processors.”
主要区别比如64bit GPRs，64bit 整数和逻辑操作，以及未来可能出现的64bit虚拟地址（下文提到当前64bit CPU通常实现48bit虚拟地址，原因是However, rather than the three-level page table system used by systems in PAE mode, systems running in long mode use four levels of page table: PAE's Page-Directory Pointer Table is extended from 4 entries to 512, and an additional Page-Map Level 4 Table is added, containing 512 entries in 48-bit implementations.主要在于4级页表的实现上，更多的虚拟地址需要更多的‘页面目录指针表’）
区别原文：
The primary defining characteristic of AMD64 is the availability of64-bit general purpose registers, 64-bit integer arithmetic and logicaloperations, and 64-bit virtual addresses. The designers took theopportunity to make other improvements as well. The most significantchanges include:xxxxxxxxxxxxxx
下面还有很多描述：
兼容64bit整数，
16个64bit GPRs，
额外的sse寄存器，
更大的虚拟地址空间，
指令指针相关数据访问，
最低sse指令包含sse和sse2（也就是amd64的机器至少支持到sse2），
nx位防攻击，
long模式下取消一些老的特性支持。 |
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IP卡
狗仔卡
楼主
显身卡
发表于 2009-4-7 17:05
64比较好吧。。。。。。。。
