k enough
lately, when playing games on my mac, it would get laggy fast, like i'd need to quit or force quit. then when i boot up my mac i get the flashing folder with the question mark inside. I'd need to wait for 30 min - 1 hour with my mac off in order for it to boot normally, how2fix.
It sounds to me like it may be over heating. Install iStat and keep a eye one the temp. When you do that report back to me if the problems start when the temps go up.