Files:

1.sh:

    true

    #!/bin/bash
    true

    for i in `seq 10000`
    do
    ./1.sh
    done

    for i in `seq 10000`
    do
    ./2.sh
    done

    11.484s
    11.590s
    11.405s

    14.273s
    14.391s
    13.847s

EDIT: for reference, sourcing the scripts instead takes an average of 0.0842s for test1 and 0897s for test2. (and all test2 trials were still slower than all test1 trials), which isn't particuarly suprising.

Inlining true takes about 0.029s