While reading this interresting article on benchmarking disks, Benjamin Schweizer pointed out a link to a python tool he wrote: benchmark disks IOs.
I made a try on different available servers.
Server 1

PowerEdge 2950 - Intel(R) Xeon(R) CPU 5160  @ 3.00GHz
Dell PowerEdge Expandable RAID controller 5 (LSI Logic SAS based MegaRAID driver, PERC 5/i Integrated)
6 disks RAID [...]