I recently migrated our Exchange 2007 server from VMware server to a new server running 3i 3.5.0 build 12369, I used VMWare standalone converter on the vmdk. I am getting extreme latency on the NIC, even pinging other machines within the same host and vswitch. I have 5 other virtuals on this system and none have the same problem.
Running on a Proliant DL385, dual opteron 2.3 quads, 16gb ram. It's just a standalone ESXi with high med and low priority resource pools Exchange is alone in the high. There are 6 VMs total though one is powered off. Storage iscsi off a netapp fas270. iSCSI is in a seperate dedicated network and I have a dual port iSCSI HBA in the server. I have two physical NICs dedicated to the network the problematic vnic is in.
So far I've installed VMWare tools, uninstalled then reinstall again. Tried e1000 and enchanced vmxnet NICs.