Fortran intrinsic timing routines, which is better? cpu_time or system_clock

Question

When timing a FORTRAN program i usually just use the command call cpu_time(t).
Then i stumbled across call system_clock([count,count_rate,count_max])<

Answer 1

I find secnds() to be the easiest way to get wall time. Its usage is almost identical to cpu_time().

real(8)::t1,delta
t1=secnds(0.0)
!Do stuff
delta=seconds(t1)