I just learned that source recorder is very useful when you have a low end graphics card but still record at 30fps. Here is a short test video I did with source recorder.
Here is how you record using Source Recorder:
1. Go into console and type in "record name"
2. Once your done recording type in console "stop"
3. Type in console "host_framerate 30"
4. Then you type "startmovie name avi" Example: "startmovie nuke avi"
(it will bring up menu. Select a codec to record)
5. Type in console "playdemo name"
(then it will play the video that you recorded really slow to render the movie @ 30fps)
(then once its finished it will go back the the Garry's Mod main menu)
6. Type in console "endmovie name"
There is also a video tutorial on YouTube just search it.