Example two-dimensional Ising model:

Averaged energy and specific heat obtained from the present method for the Ising ferromagnet on a 32 x 32 square lattice and the exact ones (both full lines). Except for a small region around the critical point (see inset for maximum of specific heat) the two curves are indistinguishable. Results of similar quality were also obtained for larger lattices (we tested L = 64, 128 and 256). The diamond symbols are data obtained using the canonical histogram method at T_c. Our method needed just 40 minutes on a Pentium (66MHz) for the 6 x 10^4 lattice sweeps performed.