for power supply, higher watt = better?

Question

should i buy a power supply with the highest watt? or should I first add up the watts that my hardwares required first and decide?

1 more question
dual channel ram (1 package includes 2 ram) = buy 2 same ram separatly?

Answer 1

It doesn't hurt to get the higher wattage. Your power supply won't have to work so hard, and that will keep internal heat down. I'm not sure about your second question. Need some clarification.

Answer 2

Don't try to add up the watts. Because a 600W power supply does not actually supply 600W; it takes 600W from the wall, converts it from AC to DC, then supplies the converted power to your components. It looses a certain amount of power in the process, the amount is called the Power Correction Factor (PCF). Or you can use the term "efficiency" to represent how much power makes it through to your components. A good newer power supply will have an efficiency of about 0.85. Also, this number will change depending on the exact amount of power it is drawing at the moment. It will have its peak efficiency and a certain point. So a 600W power supply will supply just about 510W maximum to your components (assuming it's efficiency at 100% load is 0.85).

So, the short answer is: Buy a GOOD QUALITY power supply with more power than you think you'll need. A cheap power supply will only cause problems and burnt out hardware.

Answer 3

I would go with the cheapest and lowest watt you want, but if your running expensive hardware with multiple good graphics cards then you should invest in maybe a more high end one... Also if your getting a cheap power supply you should get a power surge protected power bar because supply's blow easy when theres a power surge especially the cheap ones