The new Caltech High Performance Computing (HPC) cluster is an excellent option. Your calculations will run on a state-of-the-art resource with local support. Your research group leader has to set up an account, and there is a charge depending on how much computing time you use. Groups get up to 30 TB of free data storage, although this storage is not backed up, so groups must store primary data elsewhere. National (off-campus) computing resources like XSEDE are also available by application and can provide additional computing resources at no charge.