What is the difference between Catalyst WS-C3750E-48PD-EF and WS-C3750E-48PD-E? Is it the only 1150W Power Supply? If I need to have a full class 3 power on all 48 ports of WS-C3750E-48PD-E can I swap a power supply for 1150W to have all ports to deliver 15.4W? Or I need exclusively WS-C3750E-48PD-EF to accomplish this. Thank you.