The performance of a pulsed HF chemical laser with an F2/H2 chain reaction system is widely compared to that of an F/H2 non-chain reaction system by using a chemical laser simulation code based on the constant gain method. According to the simulation results, peak power differs little between both systems; laser pulse duration is more than an order of magnitude shorter in the F/H2 system than that in the F2/H2 system; laser pulse energy in the F2/H2 system is greater than that in the F/H2 system; difference in these energies is exponentially proportional to the inverse of the initial fluorine atom concentration; laser pulse energy per mol of HF() produced prior to termination of the lasing differs little between both systems; the thermodynamical efficiency is a decreasing function of the initial fluorine atom concentration in the F2/H2 system while in the F/H2 system it has a maximum value at the certain concentration.