Power for the test of genotypic association as a function of sample size at different genotype relative risks (GRR). All panels are for the CEU HapMap population when the number of cases equals the number of controls and a multiplicative model is used. (A) Power for the Affymetrix 100 K system. (B) Power for the Illumina 300 K system. (C) Power for the Affymetrix 500 K system. (D) Power for the Illumina 550 K system.