Just wanted to let others know something I stumbled onto, in case anyone comes along with the same issue.

Background: Ever since installing Rock (back in March) on a local Win 2012R2 VM running SQL Server 2012 Express, I was not impressed with the performance. In fact, I was a little worried about it... sure, once I had visited a page it would be fast, but even coming back a couple hours later, I would hit the Rock homepage and wait 10+ seconds. I just assumed this was beta behavior and hoped Rock's performance would improve over time.

Fast forward: Two days ago I just happened to be taking a closer look at my VM running Rock and for the first time noticed unusual CPU utilization. Digging down I saw that Windows Installer was consuming 80% CPU at regular intervals, and could also see .NET runtime optimization running over and over and over. But I hadn't applied any Win updates recently, so this behavior made no sense. A quick search led me to this article http://support.microsoft.com/kb/2793634

I installed the referenced fix for SQL Server 2012 SP1, and voila!, no more high CPU. But what I'm most happy about is that Rock now flies compared to its former performance. Sure, I take a homepage hit if the server hasn't been touched in forever, but clicking on just about anything in Rock is now very snappy... at worst a second or two for things I've never visited.

 In hindsight I should have investigated the high CPU utilization long ago, but with MS updating .NET every couple of weeks and THOSE always causing high CPU spikes, I just assumed it was that behavior. Hope this helps someone if they run into the same SQL Server bug.