@nouvo09 : merci pour ta réponse mais c'est plus complexe que ça je pense
PC ne faisant rien d'autre j'ai fait un script qui copie deux fichiers puis les efface et recommence.
Fichier 1 : Windows_7_RC.iso de 2.6Go
Fichier 2 : WindowsXP_Pro_FR_SP3.iso de 1.7Go
La vitesse de transfert est assez aléatoire donc assez incompréhensible...
sylvain@sylvainsjc-desktop:~/Documents/Telechargement$ sh trfusb.sh
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.24user 7.77system
7:12.03elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
5171376inputs+0outputs (1major+273minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.13user 4.80system
1:25.40elapsed 5%CPU (0avgtext+0avgdata 0maxresident)k
3383544inputs+0outputs (5major+258minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.20user 7.42system
5:05.13elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k
5171352inputs+0outputs (1major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.12user 4.89system
1:41.36elapsed 4%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+263minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.22user 7.73system
3:31.98elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.14user 5.02system
1:40.04elapsed 5%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.18user 7.48system
2:20.24elapsed 5%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.13user 4.87system
2:01.99elapsed 4%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.21user 7.73system
1:53.33elapsed 7%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+263minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.18user 4.98system
4:21.61elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.16user 7.54system
2:45.40elapsed 4%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+263minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.16user 5.04system
3:11.88elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+265minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.20user 7.53system
3:04.44elapsed 4%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.15user 5.18system
2:20.41elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k
3383344inputs+0outputs (0major+263minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.20user 7.51system
3:13.33elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+265minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.18user 5.17system
1:09.74elapsed 7%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso
time cp Windows_7_RC.iso /media/SYLVAIN_HDD/
0.21user 7.50system
7:16.07elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
5171248inputs+0outputs (0major+264minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/Windows_7_RC.iso
time cp WindowsXP_Pro_FR_SP3.iso /media/SYLVAIN_HDD/
0.16user 5.46system
1:04.77elapsed 8%CPU (0avgtext+0avgdata 0maxresident)k
3383320inputs+0outputs (0major+263minor)pagefaults 0swaps
rm /media/SYLVAIN_HDD/WindowsXP_Pro_FR_SP3.iso