We are in the process of developing analysis pipelines for WGS,RNA and Methyl-seq data. The first projects considers 100 patients with a common disease. All the analysis would be run on data from these patients. Our institute's computational center is offering us 5 nodes (24 CPU core, 2.6GHz clock speed, 128GB RAM memory each), I believe that necessary storage space would also be provided to us. Based on your experiences would you please tell me if having 5 nodes is going to be sufficient, I understand that there cannot be one single answer to this question but any help from you all is much appreciated.  
The two big things are 

    1) How much ram does a single instance of the "largest" program you'll run need? 

This is the only hard requirement. When I've run trinity I've needed 1TB of ram before. If I didn't have a machine with 1TB of RAM, I couldn't have run Trinity. If the program with the highest memory consumption will fit on 124gb, then that's fine. 

    2) How long are you willing to wait for things to run? 

More nodes means you can run more stuff at once. You don't really *need* them. Figure out which is more important to you, time or money? Spend more money, get more nodes, higher throughput. Save money, get fewer nodes, spend more time waiting for results. 
