After using the free version for a few months, we went ahead and bought the Server version, which opened up the SPTI option. Is there a document available that does a Pro/Con for each option?
I setup a Windows 2003 VM and loaded Starwind on it. I gave the VM 2 hard drives (each VHD is on a separate physical drive), and setup Starwind to serve up both an image file and the entire 2nd drive as a SPTI device. Hooking up to both of them via Server 2008 and the MS iSCSI initiator, I was able to sustain about 91 megabytes/sec via the SPTI device, and the image file speed would jump between 104 & 98 megabytes/sec (according to Server 2008's file copy info via Windows Explorer). I'm sure with faster hard drives in a raid setup I could get better speeds, but I digress ....
So again, why would I want to choose one over the other? The difference in speed over the gigabit connection is well ... negligible if you ask me.
<off topic>Oh, for kicks, I shared a folder from the same VM and copied over the same 4GB iso file - it barely peaked at 41 megabytes/sec and sustained about 18 megabytes/sec or so ... The test server is a Dell Dimension 8400 running ESXi v4 (P4 3.4GHz, 3GB ram, 250GB and 750GB local drives @ 7200RPM) - nothing amazing, but it works well enough for a test rig.
</off topic>Also, since we run multiple ESXi boxes here, I assume any iSCSI target Starwind serves up, I'm going to have to select the "Allow multiple concurrent iSCSI connections (clustering)" option on anything that will have 2 or more initiators attaching to it?
Mahalo for your time!
Rick