we have build our system in april-may.
Hardware is redundant:
Mainboard Supermicro X8DT3
Chasis SC836
CPU 1xIntel Xeon 5550W
RAM 24GB (6x4GB)
Raid Controller Adaptec ICP Vortex 8165BR with BB 256 Cache
HDD 16x Western Digital 1TB Raid Edition 3
NIC Intel 10gbe CX4 Dual Port
Switch
2x HP 6400cl CX4
we have 2 Citrix XEN Server as "Client"
Hardware 2xIntel Xeon 5550W with 32GB RAM and Intel 10gbe CX4 Dual
Performance Windows 2008
with write cache on: ca 90000 io/s
with write cache off: ca 25000 io/s
Performance with Citrix XEN (windows 2008 guest):
with write cache on: ca 66000 io/s
with write cache off: ca 15000 io/s
there was no differenz between raid 10 and raid 6 !
so we use raid 6 iscsi for our production system.
the perfomance measure was taken with sqlio and the folowing parameters