As first thing and generally speaking I would plug and configure all ports on each server and all ports on storage, this means not to connect random cables between ESXi hosts, storage and rest of the network but making a little project accordingly to your current environment.
I suppose that to achieve a good configuration we should know more details of your environment, for example how many VMs are running, if you have set up a cluster for your VMs, what kind of EMC storage is used (VNX, Symmetrix,Celerra, ...) and what kind of load it has to withstand...etc.
A good startup point is to set-up hardware correctly e.g. making sure all nics are used (more nics could mean more throughput if everything is fine configured) ensuring there are no single point of failure within your environment (i.e. redundant network links between your ESXi hosts - storage and between storage - rest of the network, ensuring everything is fine tuned within your EMC storage,etc.).
Next step is to achieve performance by applying best practices...a good start could be configuring network in your ESXi hosts, using vDS, implementing VLANS (or verify if there are some already there), enabling mechanisms that allow more throughput like,for example, jumbo frame, TSO, etc...
This is just my opinion...maybe someone more expert than me can advice you better!
Hope this could help you,
Regards.