If you have any questions about recording/editing/encoding techniques and software you can ask here after u have read the FAQ.
The FAQ in this thread will be edited over time.
FAQ
I'm willing to record but haven't found a good tool, yet.
There are many tools and methods for windows. I'll describe the key benefits of 3 of them.
If you can recommend any other tools, feel free to write a description and I'll add it.
1. Fraps: If you want to have full control about the quality of your footage, Fraps is the weapon of choice. It captures the video of DirectX and OpenGL applications and under Windows Vista and 7 also the Aero Desktop, if active. It has a ring-buffer feature which allows you to make sure that the greatest moments of your recording are save.
2. Bandicam: This little known tool allows you to compress the video on several ways before it's written to your hard drive. This makes it the best choice if you don't have much disk space or disk performance but still want to have control about the quality and codec. (But it's also possible to record uncompressed footage) Beside capturing DirectX and OpenGL you can also define an area on the screen which you want to capture.
3. Camstudio: If you only want to capture something quick and straightforward, you should try Camstudio. The key benefits of this program are, that it's very easy to handle, compress very well by default and, last but not least, its free and open source.
4. Mirillis Action!: This tool works best for me. (I can record at 25 FPS with almost full framerate with a single core CPU and a mid class graphics card) It has great capture performance, does compressed captures and supports CUDA for exporting a video. Make sure to check it out!
Do people with a MAC record games and so yes with what software and does it affect performance much?
I can't say much about screen recording software at MAC, I hope some other people can tell you more.
About the performance thing:
There are two factors which influence the capture performance significant:
The most significant is the CPU performance. Each frame of the video has to be grabbed out of the screen buffer and has to be encoded. This is done with multiply threads, means it's splitted into different processes which are executed simultaneously. The faster the CPU is and the more cores the CPU has, the better will be the performance in most cases (It's the programmer's job to optimize the code for multi core processors). It should kept in mind that the game itself and all other running processes taking CPU power too.
The hard disk performance is significant in almost the same manner. To understand it, we will have a look at the structure of a raw video frame: A frame is a combination of width*height pixels where each pixel can display a certain amount of colors. If we assume each pixel has a color range of true color (most likely 24 bit, 8 bit for R/G/B each) and the window size is 1280x720 pixel the formula of the size of a video frame in byte(8 bit are 1 byte) is:
1280*720*32/8 = 2764800 byte or 2764800/1024=2700 KB or 2700/1024=2,63 MB
If we assume that the video has a frame rate of 60 frames per second (that's 158,2 MB per second written to your hard disk), it's getting obvious why the disk performance is so important to keep the capturing fluent.