buffer size = 8 Kb:

Copy /unix foo using  C++ streams

real 1.39
user 0.15
sys  1.24
Copy /unix foo usign read/write

real 0.38
user 0.01
sys  0.37
Copy /unix foo usign fread/fwrite

real 0.44
user 0.11
sys  0.33


    buffer size = 512 b:

Copy /unix foo using  C++ streams

real    0m1.70s
user    0m0.21s
sys     0m1.45s
Copy /unix foo usign read/write

real    0m2.16s
user    0m0.07s
sys     0m2.06s
Copy /unix foo usign fread/fwrite

real    0m0.45s
user    0m0.11s
sys     0m0.33s