How many watts do i need?

[computernewbie2009]

hi, experts
i'm building a new computer, and it's my first time
i don't how to calculate how many watts i should buy for psu

i tried some online calculators, but they gave different results, some say 350, some say 400, some say over 500, so i'm really confused

these are the hardwares i'm going to use:

p45 motherboard
E8500
geforce gtx 260
2 DDR3 2G RAM
1 640G Hard drive
1 DVD+-RW
mouse & keyboard
Fans (i don't what kind of fan should i buy either, i think the case has 2 fans and i'll buy a fan for the cpu)
sound card and network card: included in the motherboard
usb device: a portable hard drive (it will not be connected all the time)

pls calculate the watts i need for me
and if i need to include anything else in the calculation, pls let me know
and any suggestion for the fan?

thank you

 

[o1die]

I usually recommend a corsair or pc power and cooling. For your single video card system, 600 watts should be enough in one of these brands. If you think you might want a 2 card setup some day, then 750 to 850w will be adequate. Other cheaper brands may be overated for the peak wattage under load, resulting in crashes or sparks and smoke. I bought a cheap no name brand once that lasted only 4 days. I was lucky it didn't take out my motherboard and cpu when it died.

 

[jsc]

I am powering a similar system with a 550 watt Antec:

GA-EP45-UD3L, OC'd Q6600, 4 GB RAM, 4870, 2 HD's, and 1 optical, 5 fans (Antec 900 case and HSF)

I estimate the PSU is running at about 70% load. The air coming out the back of the PSU, as measured with an electronic thermometer, is about 2 C. over ambient.

 

[theAnimal]

Good quality 400W+ is plenty. Seasonic M12 II/S12 II 430W have the required 2 PCIe connectors.

 

[computernewbie2009]

thanks for the answers, guys
i'm thinking 450w, would it be enough?

 

[theAnimal]

thanks for the answers, guys
i'm thinking 450w, would it be enough?

Good quality, yes.

 

[computernewbie2009]

Good quality, yes.

ok, thank you!