I am not sure if someone has tried it, but someone asked the same thing at Anandtech back in 2001. It looks like the extra pads were for variants of the card that used less dense SDRAM instead of SGRAM, rather than trying to double the memory to 32 MB. Even if somehow the graphics hardware could support 32 MB of VRAM (it very likely doesn't), it wouldn't do much good anyway; the Voodoo3 was limited to 256 x 256 textures at 16-bit colour, so one wouldn't be too likely to run out of VRAM at resolutions that the card can perform reasonably well at. Any newer games that would take advantage of 32 MB of VRAM likely are using 32-bit textures and/or larger textures that the chipset can't do much with anyway. :\