[ 4:40:33.95] P:\test>cut -d, -f 1-15 data\25x500000.csv >nul

[ 4:41:13.59] P:\test>

[ 4:42:48.34] P:\test>perl -lanF, -e "BEGIN{ $,=','} print @F[0..14];" data\25x500000.csv >nul

[ 4:43:25.60] P:\test>