Select the number of raw CEL files to merge into the main data table at once, prior to normalization or summarization. This parameter helps manage import of large sets of CEL files, such as Exon and Gene Level (ST) Arrays. A single HuEx CEL file can occupy considerable hard drive space during import (for example, ~156 MB per imported HuEx CEL file).
When selecting the number of files to merge at once using this parameter, you should be aware of your free hard disk space and the number of CEL files being imported. When hard drive space is limited, you should select to merge files in smaller groups (for example, 25-50 files at a time). If free hard drive space is not limited, you might be able to import and merge hundreds or even thousands (where applicable) of CEL files at a time.
Please note that performance is best when merging CEL files in larger groups. However, merging files in groups too large to be stored on the drive where the SAS temporary directory is located can cause “out of disk space” errors. Please check your computer's available hard drive space by right clicking on the drive letter, choosing Properties, and viewing the pie chart of available disk space.
