What is EM64T

[Sara.S]

I have heard this word EM64T many times while studying about CPUs and processors. Mostly i found this when i keep working for Intel processors. TO be frank i don't anything about it and as per my studies i need to know the same. So could you guys help me out please. What is meant by EM64T ?

[Hardwareman]

EM64T stands for Extended Memory 64 Technology and is the technology that Intel has released their 64-bit technology in order to compete with AMD’s 64-bit technology. It is now known more commonly as Intel 64 or the x64 and is present on all Pentium 4 6xx models, on Pentium 4 5x1 models.Introduced in 2004, Xeons (code named Nocona) were the first CPUs to incorporate Intel 64 along with other enhancements such as the PCI Express bus and DDR2 memory.Intel EM64T improves performance by allowing the system to address more than 4 GB of both virtual and physical memory.It is widely used in Intel's processors, including Pentium 4, Pentium D, Pentium Extreme Edition, Celeron D, Xeon, Pentium Dual-Core, and in the Core 2 processors.

[Joshua]

EM64T is a feature in the company's upcoming uni- and dual-processor Xeon offerings for the server and workstation market that allows the devices to work in both 32- and 64-bit modes. With the introduction of Intel 64, Intel offers 64 bits in two CPU families: the 32/64-bit x86 (IA-32) line and the 64-bit Itanium (IA-64) line. EM64T technology can only be used by 64-bit operating systems where 32-bit operating systems will continue to run under regular IA32 mode.

[aalbaiz]

EM64T was assumed that this occurred so as to compete against the Opteron and Athlon 64 lines, also known as the K8 core, from AMD.Intel EM64T provides support for 64-bit flat virtual address space, 64-bit pointers, 64-bit wide general purpose registers, 64-bit integer support, Up to 1 terabyte (TB) of platform address space. 64-bit allows an installation of up to 16 EB (exabyte) of RAM; however, current Celeron D, Pentium 4, and Xeon CPUs have 36 address lines, which can support 64 GB of RAM, while Xeon DP CPUs can hold up to 1 TB.