Thanks again. I'll probably keep poking at it, I think the 4k issue probably has to do with opensm and how it is starting as a service under Windows. Might need to run opensm under a Linux system, but seems kind of a waste to have an IB system just to run the subnet manager.
No clue on the speeds though, from iblinkinfo on another box, it detects it can run at 1x or 4x, but chooses 1x for whatever reason.
Getting this to work fully with ESXi has been becoming less of a priority now since we're going to get ConnectX-2 cards for the next order, and we're not commited at all to VMware products. Been working fine with Windows and Hyper-V so least have that route.