I have a iSCSI test setup with the following hardware:

open-e 6.0up14.8101.4221 64bit :
2x Opteron 2378 (2.4 GHz)
8 GiB Ram
Areca 1680 Controller
8x 1TB HDD Raid 5
2x Intel dualport Gigabit NIC

ESX 4:
4x Opteron 2378 (2.4 GHz)
32 GiB Ram
2x Intel quadport Gigabit NIC

Open-e provides one iSCSI target for ESX. Unfortunately i am having severe performance problems. In my opinion, testing und a virtualized Windows XP with IOmeter, i should get around 100 MiB/s read or write performance. Unfortunately, whatever IOmeter settings i try, i can't get substantially more than 50 MiB/s.

Can anybody provide me with data from his thests or any pointers how to optimize the speed?