SegaWeb.com: Features: PS2: Disappointing Technology

I remember when the PS2 was first announced and the technical specifications that were bandied about at that time: 75 million polygons/second, unlimited streaming texture potential, 48GB/s of memory bandwidth, and so on. It wasn't long after this that technology analysts began to question Sony's numbers.

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To better understand the PS2's limitations and the Dreamcast's strengths, you need only look at the available video memory for your answer. While the DC has 8MB of VRAM, the PS2 has only 4MB of VRAM. The main problem arises because a polygon takes up roughly 40 bytes of RAM. When you have 5 million of them in a given second, this amounts to 5 million/60fps = 83,333 polygons in a give frame of animation. If each of these polygons uses 40 bytes of VRAM, you will use 3.33 MB displaying these 5 million PPS. This doesn't leave the PS2 much room for it's framebuffer which uses around 1.2MB just to display the end data, not to mention that you still need to leave room for textures to put on those polygons.