I would consider my test server hosting my virtual environment to be rather powerful but it has a Octa-Core (i7 920) CPU, 24Gb of DDR3 memory and a SSD for Host and a Hybrid HDD for virtual HDD and its running on Windows Server 2008 R2 x64. The Host has two network card both connected to a Gb switch, one for the host and the other one is dedicated to the virtual machines.
On the Host I have nothing installed except Antivirus, SQL 2008 R2 and Hyper-V manager.
Last week I deleted all the test machines and installed two servers from scratch, one for CRM 2011 and one for SharePoint 2010 (both with 2 CPU and 4Gb of ram) and after the install I ran windows update to install all relevant updates from my WSUS and then I enabled RDP for remote access.
The performance via RDP was strange because sometimes the seamed fast and responsive but sometimes they where so slow and even gave me timeouts when accessing a very simple webpage hosted on them via browser from a remote locations.
When I was on the same LAN the ping from my laptop was dropping around 50% and even from the host to virtual and virtual to virtual was the same.
I looked around for solution but didn’t find anything related to my setup/issue so I started fooling around with the Hyper-V setup and updating driver etc. One thing I know that has changed since I used the host last time is the fact that I added that dedicated network card but I have updated all the drivers.
When I uninstalled the virtual network card and installed a legacy network card the issue went away. Note that the legacy network card can “only” give you 100Mb…
This is probably hardware issue, the new network card not being supported by Hyper-V but as this is a test server I don’t care….
Just wanted to let u all know 
