Compiling with different J values

I compiled audacity with different -j values in the open lab and here are the results. j1 took the least time to compile.

j1
real    6m34.068s
user 5m44.576s
sys    0m37.742s

j2
real    6m34.891s
user 5m44.713s
sys    0m38.189s

j3
real    6m39.111s
user 5m44.737s
sys    0m37.833s

j4
real    6m39.228s
user 5m46.737s
sys    0m38.582s

j5
real    6m46.783s
user    5m49.364s
sys    0m40.147s