Table 2. Averages and standard deviations of computation time for each step of GHOSTZ-GPU and GHOSTZ calculations.

	GHOSTZ (sec.)	GHOSTZ-GPU (sec.)	Acceleration Ratio
Distance calculation	1340.7 ± 45.7	46.8 ± 0.1	28.7 ± 1.0
Ungapped Extension	18554.8 ± 695.8	557.5 ± 4.6	33.3 ± 1.4
Gapped Extension	17191.5 ± 672.7	469.1 ± 0.4	36.6 ± 1.4

This profile was obtained from the calculation involving short DNA reads in metagenomic sequences of the soil microbiome (SRR407548) as queries and KEGG GENES as a database. To obtain a profile for GHOSTZ, the functions of distance calculation, ungapped extension, and gapped extension were not in-lined. To obtain a profile for GHOSTZ-GPU, the computation time of memory copy between CPU and GPU was excluded. This is because this process is hidden by CPU and GPU calculations during asynchronous execution on a CPU and GPU.