64 bit

A 64-bit processor is one that generally supports a word size of 2⁶⁴, where the constant "maxint" has the value 2⁶⁴-1, or 18,446,744,073,709,551,615. The signed version of this number can express a range of -18,446,744,073,709,551,615..0 and 0..18,446,744,073,709,551,615. The unsigned version of this number can express a range of 0..18,446,744,073,709,551,616. It also means that programs and data spaces can be much larger than on the older 32-bit and 16-bit machines.

Examples of 32-bit processors include

• Newer versions of the X86 microcomputer, Itanium and newer, AMD64 (WINTEL architecture)

Currently, 64-bit processors (X86) are enhancements of 32-bit processors, and generally can run 32-bit and 16-bit applications. The reverse, however, is not true; 64-bit code cannot run on a machine smaller than 64 bits.

See Also

• Writing portable code regarding the processor architecture
• Integer
• 32 bit

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From the Free Pascal wiki, page "64 bit", as it stood on 2020-10-10 after a change by Arent, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.