Basically, I mention my video card as the screen refuses to update itself, so if I scroll down, it still shows the top of the web page, and then bits of it appear, and then it unfreezes and scrolls down, or If i'm watching a video a pink hue will appear, and then go all blurry. and the sound will be jittery, according to VLC

"frame (computer too slow ?)
ffmpeg: more than 5 seconds of late video -> dropping frame (computer too slow ?)
"i'll have dropped frames."

it's incredibly frustating, and one more thing when i turn on my pc the apple bootloader goes on, and the screen goes amber. and deosn't load the desktop, i have to restart twice before I get to the desktop.