We measure voltage noise spectra S_V_(f) generated by current-driven vortices at various fields B including the peak-effect regime for amorphous Mo_x_Ge_1-x_ films with Corbino-disk and striplike contact geometries. Field dependences of the critical current Ic and S_V_(f) are nearly independent of contact geometries, indicating that edge effects are not important on static or dynamic vortex properties. This is in contrast to the result reported for NbSe_2_ crystals with much larger thickness. S_V_(f) at low frequency f exhibits a sharp peak just below the peak field Bp of Ic, where the characteristic time of vortex motion increases significantly. The results suggest the existence of the order-disorder transition and vortex instabilities due to coexisting vortex phases at around Bp.
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