The physics of crystalline membranes, i.e. fixed-connectivity surfaces
embedded in three dimensions and with an extrinsic curvature term, is
very rich and of great theoretical interest. Numerical simulations ar
e commonly used to study this class of models. Unfortunately, traditio
nal Monte Carlo algorithms suffer from very long auto-correlation time
s, especially near critical points. In this paper we study the perform
ance of improved Monte Carlo algorithms for simulating crystalline mem
brane, such as hybrid overrelaxation and unigrid methods, and compare
their performance to the more traditional Metropolis algorithm. We fin
d that although the overrelaxation algorithm does not reduce the criti
cal slowing down, it gives an overall gain of a factor 15 over the Met
ropolis algorithm. The unigrid algorithm does, on the other hand, redu
ce the critical slowing down exponent to z approximate to 1.7. (C) 199
8 Elsevier Science B.V.