I am currently in the process of building a new computer. This is the current specifications that I am hoping to run on.
- Intel Core i7 860
- BFG Tech 9800 GT 512 MB 256-Bit PCI-E 2.0 x16
- ASUS P7P55 LX
- Artic Cooling Freezer Pro 7 Rev 2 CPU Cooler
- 500 GB SATA hard drive
- CD Driver
- 2 case fans (1 back, 1 side)
A 500 - 550W power supply is even better. The efficiency wil be higher (usually the power supply achieves its highest efficiency when delivering between 40% and 60% of its maximum capacity). The disadvantage is the price of a higher wattage PSU. Anyway, at the long run it is a good idea because you will save money on your electricity bill and you will have a higher headroom for upgrades if needed.