You can have a look at xeon e5-2670 v2 cpus, they're relatively cheap, around $200 and have 8c/16t so in a double cpu configuration you could have 64 cores with

You can have a look at xeon e5-2670 v2 cpus, they're relatively cheap, around $200 and have 8c/16t so in a double cpu configuration you could have 64 cores with only 4 machines.