I would like to know what does reduce more the render time… RAM, CPU, or video card?
The *only* thing that will speed up final rendering is CPU speed. More RAM will speed up AMs rendering only if you don’t have enough for your scene and the renderer has to keep loading image maps on every frame. If you don’t have that prob, go for a faster CPU. A video card will (may?) only speed up quick-shaded renders, not final.