Based on some observations, I came up with a solution that *will* use 100% of your CPU bandwidth when rendering to a file, regardless of what plugins you are using.
For each CPU, run the Vegas Network Render Service (i.e. dual-CPU system should have to instances of the network render service running); this will require you to change the port number in the two config files (NetRenderClient.config and NetRenderService.config) to unique numbers each time you run a new instance of the network render service. Configure one the the network render instances to point to the other instances (in the Renderers tab).
Open up Task Manager (right click on Taskbar and select Task Manager); right click on each instance of VegSrv60.exe and select Set Affinity. Select only one CPU for each VegSrv60.exe instance, and make sure it is a different CPU for each one. When you have Vegas render thru the network render service, each segment that is rendered will have a dedicated CPU. Even when you are using the Magic Bullet plugin, the full bandwidth of your CPUs are utilized.
For each CPU, run the Vegas Network Render Service (i.e. dual-CPU system should have to instances of the network render service running); this will require you to change the port number in the two config files (NetRenderClient.config and NetRenderService.config) to unique numbers each time you run a new instance of the network render service. Configure one the the network render instances to point to the other instances (in the Renderers tab).
Open up Task Manager (right click on Taskbar and select Task Manager); right click on each instance of VegSrv60.exe and select Set Affinity. Select only one CPU for each VegSrv60.exe instance, and make sure it is a different CPU for each one. When you have Vegas render thru the network render service, each segment that is rendered will have a dedicated CPU. Even when you are using the Magic Bullet plugin, the full bandwidth of your CPUs are utilized.