You can reduce the VRAM requirement by lowering the max texture size, the slider is there for a reason.
You don't say anything about your system but, if you are low on VRAM, it's because your settings are too high for your system so, you might have to reduce some of them (like LOD radius, Autogen, etc.), GSX cannot obviously be the problem by itself but, it's clear that, if you were very *CLOSE* to VRAM exhaustion, it would be enough to just add something more detailed, and it would break up, not because of GSX, but because you were already too close to VRAM exhaustion before.