"Your workloads and networking traffic may not need increased buffers; however, these days, 4Mb of RAM isn’t a tremendous amount of memory to invest as an insurance policy against packet loss. Now, if only I could increase a few buffers and alleviate congestion on my daily commute!"http://blogs.technet.com/winserverperformance/archive/2010/02/02/increase-vmbus-buffer-sizes-to-increase-network-throughput-to-guest-vms.aspx
In order to make the change (source above) :
On the Guest OS , In the Network Adapter Properties dialog, select the Details tab. Select Driver Key in the Property pull-down menu as shown in figure 1 (click the images to see a version that's actually readable):
Record the GUID\index found in the Value box, as shown in figure 1, above. Open regedit and navigate to:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{GUID}\{index} as shown in figure 2:
Right click the index number and create two new DWORD values, entitled ReceiveBufferSize and SendBufferSize (see figure 3). These values measure the memory allocated to buffers in 1Kb units. So, 0x400 equates to 1,024Kb buffer space (the default, 640 buffers). In this example, we’ve doubled the buffer size to 0x800, or 2,048Kb of memory, as shown in figure 3:
