It would be exponentially less efficient, as the simulation algorithm used represents and operates on all 2^n possible quantum states of n qubits. If you know

It would be exponentially less efficient, as the simulation algorithm used represents and operates on all 2^n possible quantum states of n qubits. If you know nothing about QM, imagine the classical analogue: a classical CPU simulator with exactly one (say) 32-bit register, which, instead of being represented as 32 bits, is represented as 2^32 bits, exactly one of which is set to 1; the only way to determine which bit this is is to scan the entire array.