-plot 'data' using 1:2 pt 7 ps 0.2 title 'read()', \
- 'data' using 1:4 pt 7 ps 0.2 title 'recvmmsg()', \
- a1*x+b1 with lines lt 1 lc 1 lw 1 title "Linear fit for read()", \
- a2*x+b2 with lines lt 1 lc 2 lw 1 title "Linear fit for recvmmsg()"
+set yrange [0:]
+
+b1=b1/1000
+b2=b2/1000
+
+plot 'data' using ($1/1000):($2/1000) title 'read()', \
+ 'data' using ($1/1000):($4/1000) title 'recvmmsg()', \
+ a1*x+b1 with lines lt 1 lc rgbcolor "#aa0000" lw 5 title "", \
+ a2*x+b2 with lines lt 1 lc rgbcolor "#00aa00" lw 5 title ""