The 460 is at least 30% faster than the 450, clock speed isn't everything. Most power supplies have a 20+4 pin plug, I would be suprised that your computer even has a PCI-E x16 slot if it only uses a 20 pin power connector. What are the rest of your specs and the wattage ratings on the side of your PSU?
Well the motherboard does have a 24 pin psu, but I was informed that I could still plug the 20 pin and it will work fine.
Without the graphics card, will this be a problem? When I go to buy the graphics card, im planning on getting a new power supply to go along with it. I'm hoping that I can get by on the 20pin for now. If this is a bad idea, can someone say so, or will this be okay for now?
It's 2 in that they separate. The 4 pin clips to the side of the 20 pin to make the 24 pin plug that modern motherboards use. Thats not a very good PSU, although it is cheap. Even though it says 580w only 300 of that is on the 12v rail and usable. Might still be ok for a 460 but not a recommended brand.