Less than stellar, poor performance with a GTX 670 until I changed setting

I'm new to LOTRO and I also just bought a new EVGA GTX 670 FTW. I couldn't figure out why I was still getting &&&&&& frame-rates in some places (I know mmporpgs aren't known for being optimized and lag free... but still). I used EVGA's Precision tool with and on screen display to monitor my video card while playing LOTRO. When running around Bree I was seeing less than 50% GPU utilization, my card was stuck at 810 MHz (it maxes at 1254 MHz) and I was dipping down to 30 fps.
I changed the settings in the nVidia control panel under Manage 3D Settings > Programs (and here I had to add lotroclient.exe to the list of programs). The setting to change is Power Management Mode to Prefer Maximum Performance.
I don't know why but LOTRO by default doesn't seem to ask for all it can get from the card. The Kepler based cards have a variable clock frequency depending on what's needed from the program. All my other games will max it out if necessary but not LOTRO. Fortunately you can tell the card what to do.
I searched a lot trying to figure this out and came up with zilch until given a pointer by someone at the EVGA forums. I'm posting this here in case anyone searches on it regarding the 660, 670, 680 or 690 GTX cards if they're not getting the fps and performance they expect.