I work on two distinct scientific clusters. I have run the same python code on the two clusters and I have noticed that one is faster by an order of magnitude than the other (1min vs 10min, this is important because I run this function many times). I have investigated with a profiler and I have found that the cause of this is that (same code and same data) is the function numpy.array that is being called 10^5 times. On cluster A it takes 2 s in total, whereas on cluster B it takes ~6 min. For what regards the other functions, they are generally faster on cluster A. I understand that the clusters are quite different, both as hardware and installed libraries. It strikes me that on this particular function the performance is so different. I would have though that this is due to a difference in the available memory, but actually by looking with `top` the memory seems to be used only at 0.1% on cluster B. In theory numpy is compiled with atlas on cluster B, and on cluster A it is not clear, because numpy.__config__.show() returns NOT AVAILABLE for anything. Does anybody has any insight on that, and if I can improve the performance on cluster B?