Windows x64 Editions can address a full 16 TB of virtual memory by using a flat addressing model. This 16 TB is divided up into equal buckets of 8 TB of virtual address space for applications and 8 TB for the operating system.
Note: The current x64 Editions of Windows actually only use 40 bits for addressing memory, yielding an address space of 240, or 16 TB. The theoretical maximum of a full 64-bits of address space is 264, or 16 exabytes (1.6x1019).
An important consideration in the short term is that even 32-bit applications will benefit from increased virtual memory address space when running in Windows x64 Editions. Applications that are compiled with /LARGEADDRESSAWARE, as would be required to take advantage of the /3GB switch in 32-bit Windows, will automatically be able to address 4 GB of virtual memory without any boot time switches or changes to x64 Windows. Plus, of course, the operating system does not have to share that 4 GB of space, so it is not constrained at all.
|
