Thank you for the replies.
Zecow :
no... CPU wise there's speed step to help out witht he power consumption. OC'ing will consume more power as well.
I assume your "no" means that I don't need to worry about the power efficiency since CPU does the job through something called "speed step." I am not willing to do overclocking...I'm a newbie. Besides, considering the decreasing price of Intel Core 2 Duo E8500, relying genuinely on the market rather than my knowledge, hopefully, I don't need such last resort.
If CPUs have such function, do I need to simply choose power supply unit according to the estimated maximum usage of the power resource? Wow...I said "simply" but, actually, I have little idea on how to choose PSU. According to some reviews on the net, Antec, which is known for their cases, seems to be a good maker with Earthwatts for cost performance with a bit of noise and a bit costy Signature with efficient overall quality. However, what do I need to check the maximum power the machine need?
Also, I'd like to update the system if the market prices of some components go down. So, there should be some free room especially when the CPU calculates the efficiency. Could you give me some pieces of advice?
The below is the system I'm thinking of.
Case:Antec 1200
CPU:Intel Core 2 Duo E8500
Motherboard:Asus P5Q-E
Memory:Umax Pulsar DCDDR2-4GB-800
Graphic Card:ATI Radeon 4850 or 4870 depending on the price
Something like above. I'm not going to spend much money on a hard disk(s) and an optical media device. For hard disk, I'd like to take speed than amount, though.