My desktop has a 250W power supply currently. However, I recently installed an ATI 5670 and it seems to run alright, but I just found out the system requirements say I need a minimum of 400W. Does this mean just for the graphics card? Do I have to take in account all my other components when potentially purchasing a new one? Am I missing out on full performance by giving it less power? If so, how many watts should I purchase?
I think yours system should be fine, but check the label to see how many 12volt amps there are.
It is important to know that my system is a sff system optimized for low power consumption.
I am not saying there is not a use for having a bigger power supply. Less stress on the power supply and better efficiency if you use 50% of the total power.
My main system has an 850 watt psu. Overkill for a system that has trouble breaking 300-350 watts(I7 920 @ 3.5 + 5870 + 5 hard drives and 6 sticks of memory.....see a trend here it takes lots of hardware to NEED 600 watts).
But, Sorry, a 250watt supply is NOT adequate for a system with any add in graphics card. Also, there really are no "good" 250watt supplies made as they are all design for low end low power systems without add in graphics cards......so don't worry about looking up the power on 12volt rails. And after they are a few years old, NO supply will output it's original rated power due to capacitor/component aging.
This site recommends a 400watt supply for your card. That's fine from most entry level GPUs & systems. You can buy a 400watt supply from a good brand like Corsair on sale for about $20 (CX series...)
I beg to differ.
I am not trying to downplay the importance of a good power supply. And i do recommend corsair power supplies, but, this(E6300 + 5670) system is not a power hog in any way. If you are unsure, goto your local hardware store and grab a power meter.
system above mentioned(my media center)
Maybe something a bit different
X4 955 @ 3.7 and a 4870 or was it a 5870, do not even remember any more. sold that system.
All those are at the plug tests so the DC power use is actually lower.