An IBM demo shows the contrast. A terrain rendering program lets you fly over Mount Rainier at 1,300mph. Cell crunches through millions of lines of topographical and photographic data per second to paint topographically accurate, photo-quality pictures at a movie-quality 30 frames per second. On a similar program a Pentium takes more than two minutes to sketch a single frame.
The article is worth reading, that paragraph above is worth reading again. Think about what this thing is going to do when applied in engineering or architectural design, bio-research, and chemical modelling.