CISC372 Lecture Notes - Lecture 1: Uniform Memory Access, Kilowatt Hour, Parallel Computing

• School: University of Delaware
• Department: Computer and Information Sciences
• Course: CISC372
• Professor: Stephen Siegel

Document Summary

Prediction in 1965 paper that density of transistors in cpus will double every year. Power consumption is measured in watts (w) 1 j/s. 1 kilowatt hour (kwh) is also a unit. One watt = one volt times one ampere. 30w processor running for 1 hour consumes 108000 j. Total amount of energy consumed by consuming 1000 watts for an hour. Frequency peaked around 2005, multiple cores took off. Harder to find ways to speed things up with more transistors. Energy is converted into heat, which can easily damage the processors solution: instead of making processors faster, make more processors. Power frequency is roughly proportional to the cube of the frequency. Cpu2 has 2 cores running 30% slower comparison: Cpu2 uses less than 70% of the power of cpu1. Cpu2 has 2(. 7) times the original computing power. Win win, but this assumes that the programs can use the two cores concurrently.