We are in the process of setting up two virtualization servers (DELL R710, Dual Quadcore Xeon CPUs at 2.3 Ghz, 48 GB RAM) for VMware VSphere with storage on a SAN (DELL Powervault MD3000i, 10x 500 GB SAS drives, RAID 5) which will be attached via iSCSI on a Gbit Ethernet Switch (DELL Powerconnect 5424, they call it "iSCSI-optimized").
Can anyone give an estimate how much faster a fiber channel based solution would be (or better "feel")? I don't mean the nominal speed advantage, I mean how much faster will virtual machines effectively work?
Are we talking twice the speed, five times, 10 times faster? Does it justify the price?
PS: We are not talking about heavily used database servers or exchange servers. Most of the virtualized servers run below 3-5% average CPU load.