Poster presented at NanoMaterMan symposium on the 16th May 2017 in Manchester UK. Advances in the synthesis of porous materials have introduced an enormous variety of possible materials for addressing issues such as carbon capture, catalysis and hydrogen storage. To evaluate these materials, a computational screening method is needed which will require GCMC simulations. However with a variety of programs available to do this, it is not clear which can be trusted and which will perform quickest. In this work we assess the computational performance of five freely available programs. We first quantify the rate of sampling by each program, then critically compare the performance of the programs.