I am building a new system and don't really know what PSU I should be getting. I am currently looking at the Antec EarthWatts EA-650 GREEN 650W power supply. Using the Thermaltake Power Supply Calculator, it looks like I'll need just above 600 watts, but I'm not sure about Amp requirements. The computer will be used for gaming and graphics/cpu intensive programs. I'm on a pretty tight budget, but any suggestions are helpful and much appreciated.
- i7 2600k (OC from stock 3.4 to 4.0)
- Gigabyte GA-Z68X-UD4-B3 MoBo
- 2x G.SKILL Ripjaws X Series 8GB (2 x 4GB)(16GB total)
- 1x Seagate Barracuda 1TB 7200 RPM HDD
- 2 AMD Radeon 6870 Crossfire X
A good 650W PSU will be plenty for a system with two 6870s. However such a system also needs four PCIe connectors, unfortunately most 650W PSU only come with two. You could use peripheral to PCIe adapters if you are happy to use them.
I haven't heard of Xigmatek before. It has an 80+ bronze certification which is nice, but is this a well trusted brand? Would it be better to get a 700 watt system with 4 PCIe connectors that might be the same price, by a "more recognized" brand name?
Although a 650w unit is good for crossfire 6870's, the fact that your're also overclocking your CPU (and most likely the gpus) means that your going to run nearly 70-80% of the PSU's capacity under load. In that circumstance, i'll recommend you go towards the 750w units just to get some breathing room for yourself.