  We study a system of N D3-branes in which open string tachyons survive in the
low energy alpha' -> 0 limit. We compute the height of the tachyon potential
both in the weak and strong couplings by using N=4 super Yang-Mills and the
dual AdS_5 descriptions respectively. We find an exact agreement between the
two descriptions in the large N limit. This provides an example of
gravitational duals of open string tachyon condensation.
