4x Antialiasing is worthless, unless your monitor is of limited resolution.
The reason for this is that when you turn on 4x antialising, what the card is doing is rendering an image twice as wide and twice as tall... At 800x600, that means 1600x1200 res. It then scales this down setting each pixel to the average of the 4 pixels at that sampling location in the larger image.
It's worthless, because you could just be displaying the graphics in that higher resolution and be getting better performance! Honestly... would you rather look at a blurry 800x600 image, or a sharp 1600x1200 image? I think the answer is obvious. :-)
But as I said, it is useful if you say, have a monitor which can only do 1024x768. Then you can improve the image quality with antialiasing. That's why games for consoles use antialiasing. TV's can only do 640x480.
The reson for your slowdown if you haven't yet figured it out is because you're really rendering the scene at 1600x1200 when you have antialiasing on. So naturally your card chokes.
Try 1152x864 without antialiasing. Or 1280x960 (or 1280x1024 if you're using an LCD screen with that as a netive resolution) It'll look nice and sharp and be reasonably fast.
The reason for this is that when you turn on 4x antialising, what the card is doing is rendering an image twice as wide and twice as tall... At 800x600, that means 1600x1200 res. It then scales this down setting each pixel to the average of the 4 pixels at that sampling location in the larger image.
It's worthless, because you could just be displaying the graphics in that higher resolution and be getting better performance! Honestly... would you rather look at a blurry 800x600 image, or a sharp 1600x1200 image? I think the answer is obvious. :-)
But as I said, it is useful if you say, have a monitor which can only do 1024x768. Then you can improve the image quality with antialiasing. That's why games for consoles use antialiasing. TV's can only do 640x480.
The reson for your slowdown if you haven't yet figured it out is because you're really rendering the scene at 1600x1200 when you have antialiasing on. So naturally your card chokes.
Try 1152x864 without antialiasing. Or 1280x960 (or 1280x1024 if you're using an LCD screen with that as a netive resolution) It'll look nice and sharp and be reasonably fast.