set size 0.5,0.4
set ylabel "seconds"
set xlabel "Megabypes of data" 
set key top right
set nologscale y  
set xrange [0:30000]
set yrange [0.5:150]
set xtics ("0.35" 1800,     "1.5" 7500,  "3" 15000,  "6" 30000)
set terminal postscript eps
set output "sizet.eps"
plot 'sizet.dat'  using 1:2 title "setup time" with linesp 1 1,\
     'sizet.dat'  using 1:3 title "total time" with linesp 1 2