The game that needs 128MB of VRAM constantly would be something new (beside 3D shooter which I don't like anyway) ... I have a 64MB card (9700) and no problem with it (Age 3 on next to full detail).
But a single texture with 16MB that would definitely be there constantly, would cut the remaining VRAM down to 48MB effectively which might might be enough or too less, depending on the amount of stuff going on on the screen.
And I fear your conclusion is wrong. If you check out notebooks for example, you will see that there are quite some which come with X600 / X700 and similar cards but only 64MB onboard ... New cards do not mean that they waste energy on VRAM not really needed ... Its not the error of the GPU maker, that Mark still didn't write the little bunch of code for DXT compression which solves this kind of problems very effectively (sad that Tom's DLL had some stability problems with new cards, ATI and different drivers ... it was a really great addition :( )
But a single texture with 16MB that would definitely be there constantly, would cut the remaining VRAM down to 48MB effectively which might might be enough or too less, depending on the amount of stuff going on on the screen.
And I fear your conclusion is wrong. If you check out notebooks for example, you will see that there are quite some which come with X600 / X700 and similar cards but only 64MB onboard ... New cards do not mean that they waste energy on VRAM not really needed ... Its not the error of the GPU maker, that Mark still didn't write the little bunch of code for DXT compression which solves this kind of problems very effectively (sad that Tom's DLL had some stability problems with new cards, ATI and different drivers ... it was a really great addition :( )