From Asus Support showing all CPUs that are compatible with your motherboard: M4A785-M CPU Support | Motherboards | ASUS Global
If you want to find out the Spec of the CPU that you might purchase for your new Motherboard. This website has all the specs for all the CPU ever made including the latest.: http://www.cpu-world.com/CPUs/
Note: Need to find out what version of BIOS/UEFI your motherboard has installed. Then go to the list I linked above and look at the CPU that you want to install and be sure your motherboard has the correct BIOS installed to support it.