# Computing power

**Computing power** has been measured in various ways over time. In the distributed computing field and for supercomputers, FLOPS (or teraFLOPS (TFLOPS) or petaFLOPS (PFLOPS)) are normally used. GIMPS has also used 3 other measurements over its lifespan (P90 years, PII-400 years, and GHz-days).

## Contents

## MIPS

**MIPS** stands for "**M**illions of **i**nstructions **p**er **s**econd"...

- See [1]

## FLOPS

**FLOPS** stands for **FL**oating point **OP**erations per **S**econd. Supercomputer ratings usually derive theoretical peak FLOPS as a product of number of cores, cycles per second each core runs at, and number of double-precision (64 bit) FLOPS each core can ideally perform. Although not an SI unit, the convention is to use the SI prefixes, such as giga-, tera-, and peta-. GIMPS, via PrimeNet has been producing greater than 50 TFLOPS (as of February 2011).

## P90 years

The calculating effort one 90 MHz Pentium computer produces over the course of 1 calendar year (365 days). Because of the early adoption of this unit by GIMPS, other distributed computing projects also adopted this unit to measure the relative contribution of users.

## PII-400 years

A unit that was only briefly used. One PII-400 year equals 5.5 P90 years.

## GHz-days

The work accomplished by one core of a hypothetical 1GHz Core 2 Duo CPU in one day. One P90 year equals 5.075 GHz-days. 1 TFLOPS equals 500 GHz-days, thus 1 P90 year is about 10 GFLOPS.