User:Md.haidar.sharif


 * Performance Ratio Performance Ratio is the ratio between the execution time of one instruction (e.g., sqrt(x)) of an old processor and that of a new processor with corresponding compiler. For example, in Alpha 21264 CPU, to calculate one 1/sqrt(x) in support of gcc with optimizing options -O3 -funroll-loops takes the execution time 142.99ns(nanosecond) and for the same Alpha 21364 CPU takes 103.99ns. Consequently, the Performance Ratio is (142.99/103.99 = ) 1.375.

Ref: High Performance Computing of 1/sqrt(x) and exp(x)&exp(-x) in Alpha, Intel, and Opteron Processors. [MSc Thesis 2006, University of Duisburg-Essen]