As long as your MB had the required PCI-e slot, it should work with the current cpu.
A faster cpu would not hurt, but is not "needed" to make the video card work.
What you need is a free(unused or the same slot as the last video card if it was pci-e x16) x16 PCI-e slot on your motherboard.
And you need a sufficient power supply to run it as well. Nvidia recommends 500 watts, but that depends on the rest of the system. A quality(plenty of 12 volt amperage unlike some cheap 500 watt units with less 12 volt amperage then a 300 watt unit) 400 watt(this leaves some extra room) unit should be fine for more users.