I repeat the test with 1.5GB file ( 1519MB ) and it take 30s ( 50.6MB/s ) so I think that my theory is correct , if I follow this theory this mean that you need to have enough RAM to buffer every simultaneous writing to all target if you want the maximum speed of your hardware. I think that possibility to put swap space on a separate drive like SAS 15K could be a great way to reach constant good speed without putting 16GB of RAM in your target server, Open-E do you think that its possible?

Keven
Have a good day!

PS: I'm Open to do some test.