How to Keep Material preview 1 to 1 scale

Hi,

Is there a way to keep the material preview at a 1 to 1 scale when changing the material scale with the mapping node in the cycles material editor? The texture in the preview gets either too large or too small depending on how you scale the texture of course. It would be nice if the material preview could stay 1 to 1 or we could adjust the preview to look best regardless of the mapping scale.

I know if i manually scale the UVs up or down, it does not effect the preview. But I like to try to keep UVs in the UV space.

If this is possible please let me know.

Thanks