64-bit processor

64-bit processor

A 64-bit processor is a microprocessor with a word size of 64 bits, a requirement for memory and data intensive applications such as computer-aided design (CAD) applications, database management systems, technical and scientific applications, and high-performance servers. 64-bit computer architecture provides higher performance than 32-bit architecture by handling twice as many bits of information in the same clock cycle.

The 64-bit processor is backwards compatible with older applications and operating systems; it detects whether an application or operating system is 16-bit, 32-bit, or 64-bit and computes accordingly. This is essential for enterprise situations where purchasing new software is not feasible.

Intel, IBM, Sun Microsystems, Hewlett Packard, and AMD currently develop or offer 64-bit processors.

Clock Cycle

In a computer, the clock cycle is the time between two adjacent pulses of the oscillator that sets the tempo of the computer processor. The number of these pulses per second is known as the clock speed, which is generally measured in Mhz (megahertz, or millions of pulses per second) and lately even in Ghz (gigahertz, or billions of pulses per second). The clock speed is determined by a quartz-crystal circuit, similar to those used in radio communications equipment.

Some processors execute only one instruction per clock cycle. More advanced processors, described as superscalar, can perform more than one instruction per clock cycle. The latter type of processor gets more work done at a given clock speed than the former type. Similarly, a computer with a 32-bit bus will work faster at a given clock speed than a computer with a 16-bit bus. For these reasons, there is no simple, universal relation among clock speed, "bus speed," and millions of instructions per second (MIPS).