[CentOS] Vsftpd & Iscsi - fast enough

To extend space on our 64-bit centos FTP servers, we are considering 
setting them up to work with an existing PromiseRAID system via iscsi.

-just curious if anyone here knows if iScsi is fast enough to serve up 
all the images?

-might it be something where we get dedicated cards and put the iScsi 
traffic on its own Vlan?

Just curious if this would hold up under alot of traffic, like weather 
images and the like...

-karl