I have been looking at SignalR from last few days. Using this I have created an Admin Dashboard to get realtime information about a database table. Basically this table gets
You should review the Performance Section of the SignalR Wiki on GitHub. This provides some really good guidance for the following:
Additionally, it states the key Peformance Counters to monitor when performing load testing of your application. Which IMO you should do to truly have an understanding of how your application is going to perform and make adjustments as necessary for your specific scenario.
Finally, there is a link to Crank the recommended tool for generating client load with SignalR.
Update: Link to Crank is now current.