I know this is a silly question, but did you check your SFP cable to make sure it is an Intel based 10Gb sfp? If so, and you are having these issues, it sounds like it could be a driver issue or a configuration issue. If I remember right, the 5 and 7 series intel cards can have issues without "intel" cables. Also Check your "SMB" file services settings and see where the minimum and maximum are configured for. I use SMB1 for the minimum and SMB3 for the max. Check your other settings under file services too. Anything not needed should be disabled. Check all your vm switches, port groups, kernels etc. Make sure everything is set to jumbo frames. MTU 9000. Verify matching drivers/firmware, updates etc as well. Check BIOS to make sure cards are registering as 10GB as well. Post some screen shots too if you can. That will help a lot of us narrow it down for you.
If you haven't yet, also upgrade your vmware to the 6.7U1 from dell https://www.dell.com/support/home/us/en/04/drivers/driversdetails?driverid=53n67