Actually 3-5 for current gen. And you don't count all other things that are necessary for practical system: PCI-E connectors, RAM, Ethernet PHYs, etc. P.S. I b

Actually 3-5 for current gen. And you don't count all other things that are necessary for practical system: PCI-E connectors, RAM, Ethernet PHYs, etc. P.S. I believe in 64 in 2U, though.