Frequently Asked Questions for Intel® Extended Memory 64 Technology

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Product Information & Documentation

000005898

12/27/2019

What is Intel® Extended Memory 64 Technology (Intel® EM64T)?
Intel® Extended Memory 64 Technology (Intel® EM64T) is a technology that enhances server and workstation platforms with 64-bit addressability and related instructions.

Which processors support Intel Extended Memory 64 Technology?
Since Q4 of 2006, all mobile, desktop, and server processors based on the Intel® Core™ Microarchitecture have supported Intel® EM64T.

Which 32- and 64-bit modes are available, and under which conditions? Can I run 32-bit applications on an Intel® Processor using Intel Extended Memory 64 Technology?

 

Legacy Mode Compatibility Mode 64-bit Mode
32-bit operating system 64-bit operating system 64-bit operating system
32-bit applications 32-bit applications 64-bit applications
32-bit drivers 64-bit drivers 64-bit drivers
  4 GB address space 64-bit flat virtual address space
  GPRs are 32-bit GPRs are 64-bit