Memory Limitations
See also: x86-64 (Virtual address space section)While register sizes have increased to 64 bits from the previous x86 architecture, memory addressing has not yet been increased to the full 64 bits. For the time being, it is impractical to equip computers with sufficient memory to require a full 64 bits. As long as that remains the case, load/store unit(s), cache tags, MMUs and TLBs can be simplified without any loss of usable memory. Despite this limitation, software is programmed using full 64-bit pointers, and will therefore be able to use progressively larger address spaces as they become supported by future processors and operating systems.
Read more about this topic: Long Mode
Famous quotes containing the words memory and/or limitations:
“The memory of most men is an abandoned cemetery where lie, unsung and unhonored, the dead whom they have ceased to cherish. Any lasting grief is reproof to their forgetfulness.”
—Marguerite Yourcenar (1903–1987)
“That all may be so, but when I begin to exercise that power I am not conscious of the power, but only of the limitations imposed on me.”
—William Howard Taft (1857–1930)