Since this question is related to computation, I decided to post here. Hopefully it will be seen as appropriate.
I've just started running atmospheric and oceanic models, and I realize that I need more cores, memory, and disk space than my current desktop has. My institution has a high performance computing service, where researchers can rent cores at a fixed price per core per month. No one in my research group has used this service, but instead run jobs their beefed up machines. However, several other research groups in the department pool funds and take advantage of the computing service.
Now I need to make a decision as to whether to purchase a new machine with 60 GB of RAM, or rent cores from the computing service. What factors should I consider in making this decision? What are the advantages of using a computing service than to purchase a dedicated machine?