My eMac has started experiencing frequent system freezes (sometimes as often as every 10-15 min). The kernel panic screen never pops up. I disabled all plug-ins, etc and the problem continued. I tested the RAM, there seems to be no problem there. Since all my important files are on an external drive I decided to do a complete erase and reinstall on the system drive. Still no resolution to the problem. I've started to notice some artifacting on the screen, which leads me to believe the the problem might be with my graphics card. My question is can a bad graphics card cause system freezes or should I look somewhere else for the problem?