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