Performance per watt

In <a href="/facts/Computing/Kghtm9fX">computing</a>, performance per watt is a measure of the <a href="/facts/Energy_conversion_efficiency/gSqXlWoI">energy efficiency</a> of a particular <a href="/facts/Computer_architecture/tHtwxgR2">computer architecture</a> or <a href="/facts/Computer_hardware/8jSjsCNv">computer hardware</a>. Literally, it measures the rate of computation that can be delivered by a computer for every <a href="/facts/Watt/VK8oqRrm">watt</a> of power consumed. This rate is typically measured by performance on the <a href="/facts/LINPACK/2VtBJ2va">LINPACK</a> benchmark when trying to compare between computing systems: an example using this is the <a href="/facts/Green500/7V9TFXld">Green500</a> list of supercomputers. Performance per watt has been suggested to be a more sustainable measure of computing than <a href="/facts/Moore%2527s_law/90CSekhl">Moore's Law</a>.
System designers building <a href="/facts/Parallel_computing/nQzcpzQt">parallel computers</a>, such as <a href="/facts/Google_search_technology/WeRBWwtd">Google's hardware</a>, pick CPUs based on their performance per watt of power, because the cost of powering the CPU outweighs the cost of the CPU itself.
Spaceflight computers have hard limits on the maximum power available and also have hard requirements on minimum real-time performance. A ratio of processing speed to required electrical power is more useful than raw processing speed.

Performance per watt open-in-new

Performance per watt