Hmmm...I took another good look at it and used GTX 285 pcb where the memory chips are stacked as close side by side. I think Fermi chip is probably somewhat smaller then G200-B3 but not by a huge margin.
http://ic.tweakimg.net/ext/i/imagelarge/1267547764.jpeg
http://images.bit-tech.net/content_i...-285-1gb/7.jpg
oh there is also this
http://www.heise.de/imgs/18/4/8/9/6/...714eca01e.jpeg