Speedup of BLASTX searches for differently sized queries with and without query splitting. Different sized pieces of [Genbank:NC_007113.2] were searched against a set of human proteins. The query length in kbases is on the x-axis, with a log scale. On the y-axis is the fractional speedup, which is defined as (Tbaseline/Tblastx) - 1. Three searches were performed with both the baseline and the blastx applications (for each data point), and the lowest time for each application was used.