Memory limitation windows

The following table specifies the limits on memory and address space for supported releases of Windows. Unless otherwise noted, the limits in this table apply to all supported releases.

Windows 8. Windows Vista: Limited only by kernel mode virtual address space and physical memory. Limited by available kernel-mode virtual address space or the SystemCacheLimit registry key value. Windows Vista: Limited only by kernel mode virtual address space. Starting with Windows Vista with SP1, system cache virtual address space can also be limited by the SystemCacheLimit registry key value.

Any X64 Windows or X86 Server release can. The limit that these versions impose is the highest permitted physical RAM address, not the size of the IO space. For example, drivers could map the "lost" memory regions located above 4 GB and expose this memory as a RAM disk.

Physical Address Extension. Memory and Address Space Limits The following table specifies the limits on memory and address space for supported releases of Windows. Windows 8. Windows Vista: Limited only by kernel mode virtual address space and physical memory. Any additional feedback? In this article. Windows 8. Windows Vista: Limited only by kernel mode virtual address space and physical memory. Limited by available kernel-mode virtual address space or the SystemCacheLimit registry key value.

Windows Vista: Limited only by kernel mode virtual address space. Starting with Windows Vista with SP1, system cache virtual address space can also be limited by the SystemCacheLimit registry key value. This data structure is used to set up the addressing of almost all of the Windows usable memory in the system.

This table has room for descriptors. Each of these descriptors, in turn, can address up to 64K of memory. The MB value is determined by multiplying the size of the number of possible descriptors by each descriptors maximum size.

In a typical Windows system, the average descriptor size is much smaller. The average descriptor size is probably 32K. This yields a limit half as big: MB. The MB limit of enhanced mode Windows 3.

Normally the total amount of virtual memory is four times as much as the total amount of physical memory that Windows can access. Because both of these items are limited to MB, the following is generally true:. The actual virtual memory size stays at MB once you reach 64 MB of total physical memory, and never gets any bigger. Note that in the preceding paragraph, physical memory is referred to as "total physical memory.