We investigated the power afforded by seven different genotyping chips: the 100 k, 500 k and 6.0 chips from Affymetrix (www.affymetrix.com) and the 300 k, 610 k, 650 k and 1 M chips from Illumina (www.illumina.com). These chips sets differ in the way in which the SNPs are chosen and the total number of SNPs assayed.
