  Entanglement is considered to be one of the primary reasons for why quantum
algorithms are more efficient than their classical counterparts for certain
computational tasks. The global multipartite entanglement of the multiqubit
states in Grover's search algorithm can be quantified using the geometric
measure of entanglement (GME). Rossi {\em et al.} (Phys. Rev. A \textbf{87},
022331 (2013)) found that the entanglement dynamics is scale invariant for
large $n$. Namely, the GME does not depend on the number $n$ of qubits; rather,
it only depends on the ratio of iteration $k$ to the total iteration. In this
paper, we discuss the optimization of the GME for large $n$. We prove that
``the GME is scale invariant'' does not always hold. We show that there is
generally a turning point that can be computed in terms of the number of marked
states and their Hamming weights during the curve of the GME. The GME is scale
invariant prior to the turning point. However, the GME is not scale invariant
after the turning point since it also depends on $n$ and the marked states.
