I was going through the VPc documentation and stumbled upon this
Single Homed Fabric Extender vPC Topology
The Cisco Nexus 5000 Series switch can support up to 12 configured single homed Fabric Extenders (576 ports) with this topology however only 480 dual homed host servers can be configured in a vPCs with this configuration.
Is there a specific reason for supporting just 12 single homed FEX
How does the calculation of 480 dual homed servers is arrived
I have this problem too.