Every single game i play runs at a perfect 60fps or 30fps but it always crashes about 15-20 minutes into gameplay. I am using the latest build on windows 8. If you would like more info all my settings are defult, i have not changed anything. Thanks for the help
Try deleting the ShaderCache folder in C:\Users\<User>\Documents\Dolphin Emulator
Also try:
1) Update drivers, Windows updates, DirectX Web updater, and latest version of Visual C++ (some components may be missing)
2) Make sure under Power Management in Windows you're running in High Performance.
3) Use the OpenGL backend on one of the latest dev builds, as it is faster than D3D.
Are you on a laptop? If so, this could be an overheating problem. Or it could be an Intel HD integrated graphics problem. Not enough info to really know for sure.