We had similar issues recently on VMware where VMCI drivers were installed by default. It was causing irregular lockups which was finally resolved by turning this option off. We have advised Sage of this. See the following for more info:

serverfault.com/.../vmware-tools-potentially-locking-files-folders-on-windows-server

I'm wondering whether users could share there network performance.
I've set up a new server with 2 Hyper-V 2012 R2 VMs on it.
In the past I would always install SQL server 2012 and Accpac 6.2 on the same machine. I've done it differently this time and this would obviously have an effect on performance.
I've been testing with teh Accpac data integrity check and the propagate database function under Accpac database setup.
With Accpac and SQL server installed on the same VM those tasks finish at least twice as fast.

Because I'm curious whether I can improve my settings, my question is what your network throughput is when running the 'propagate' function under database setup - assuming you run separate VMs for SQL and Accpac.

I'm only looking at task manager in server 2012 r2 while this process is running.
It hovers around 8Mbps.Both VMS use the same virtual switch. On the host 2 NICs are teamed up. VMQ enabled. Broadcom NetExtreme NiC's

Would be curious what your network throughput is.
Thanks