Dear all i'm trying reading Affymetrix microarray data using ReadAffy command,but i get the error: Error in read.affybatch(filenames = l$filenames, phenoData = l$phenoData, : Calloc can't allocate memory (1819626853 of 1) Warning messages: 1: In read.affybatch(filenames = l$filenames, phenoData = l$phenoData, : Reached total allocation of 1535Mb: see help(memory.size) my memory size is 2GB and this data are from S.Raphael Hospital(33 arrays).In the previous simulations (for training) i worked on data from GEO database and i've never had problems in making all the analysis (reading,normalization,etc.), also with the same number of arrays of this. Now i can't read a single microarray.I don't understand this difference by what is caused. Thanks for your attention and help. Best regards Fabio Dezi Department of Biomedical Engineering Polytechnic University of Milan