i am not sure but from my understanding those 3mb just are some kind of faster cache but of course you can use more memory for textures. you just have to look at wii games. if you subtract the framebuffer almost nothing is left from those 3mb and the games don't look as if they only used a few kbs for textures.

consoles often work differently. it's possible that they have a lot more memory bandwidth for example and use some kind of streaming technology. otherwise most ps2 games wouldn't be possible either with the limited memory of the ps2.

<edit>i guess this also is for textures which isn't that bad for the low screen resolutions the wii uses.
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