!------------------------
!           test sequential file read/write
Program Main
character :: Txt2*8, Txt*8
Integer, parameter :: N=4*1024**2, M=100, Nsm =1024, Msm=100000
Real*8  :: A(N),B(Nsm)

A(:) = 0.
Size = 8.*float(N)/1024.**2*M
write(*,*) ' File size= ',Size,'MB',' Record=',8.*float(N)/1024.**2,'MB'
Do j=1,3
   Open(10,file='test.write.dat',form='unformatted')
   call system_clock(i1,i2)
      call cpu_time(t0)

    Do i=1,M
       write(10) A
    end Do
   close(10)
   call cpu_time(t1)
   call system_clock(i1b,i2b)
   wc = float(i1b-i1)/i2b
   write (*,'(4(a,g12.4))')   ' cpu time (seconds) =',t1-t0,   &
        ' wall-clock time=',wc,' IO (Mb/sec)=',Size/wc
   !call system('/bin/rm test.write.dat')
end Do

!            small records
B(:) = 0.
Size = 8.*float(Nsm)/1024.**2*Msm
write(*,*) ' File size= ',Size,'MB',' Record=',8.*float(Nsm)/1024.**2,'MB'
Do j=1,3
   Open(10,file='test.write.dat',form='unformatted')
   call system_clock(i1,i2)
      call cpu_time(t0)

    Do i=1,Msm
       write(10) B
    end Do
   close(10)
   call cpu_time(t1)
   call system_clock(i1b,i2b)
   wc = float(i1b-i1)/i2b
   write (*,'(4(a,g12.4))')   ' cpu time (seconds) =',t1-t0,   &
        ' wall-clock time=',wc,' IO (Mb/sec)=',Size/wc
end Do
   call system('/bin/rm test.write.dat')


 end Program Main