How To Choose the Right Power Supply When Building a Computer

[imdaman]

In the next few weeks, I plan on building my own computer. The problem is that I don't know how to choose the right power supply for my computer. I know that I need to have an psu with enough wattage to run the comp. but is there any way to calculate the amount of watts i need? this would be somewhat of a gaming pc with probably a phenom cpu and a gtx 260 video card. Say the computer would need 500W to run, than what adequate W i should get? (i dont want to buy a psu that has more watts than the comp needs and i dont want one that doesnt have enought power)

furthermore, how do i choose psu with the right connectors to the mobo, video card, etc?

Any help would be appreciated!

[Noahtuck]

Google is our friend

http://extreme.outervision.com/psucalculatorlite.jsp

http://www.antec.outervision.com/

http://educations.newegg.com/tool/psucalc/index.html

There are more but that was just a quick search on google.

As for the connectors, If you are going to have Sata drives, just make sure the PSU has Sata power connectors, but most do, and so forth.

Personally, i'd buy a bit larger then you think you need because more power can't hurt and you always have spare for when you add a new HDD or something down the line.

But you do not want to be underpowered.

[juststarting]

Anyone know which PSU has longer cables for a bottom mount? And modular with long cables?

[dfisher052]

Unless you're building a super computer for extreme gaming, 500 watts should be sufficient. More is always better, less is not.

[imdaman]

say it only take 500 watts, if i buy a 600W one just for safety and not really use the 100. does the psu conserve the watt or will it waste it and raise my electric bill?

[redwudz]

It would depend on the efficiency of the PS. A 700W PS will likely use more power at idle than a 500W, but not much more. Many PS's now are 80% efficient or better, so not much wasted power. And just the power rating doesn't tell you much. It depends on which rails that power is on. Generally, though, a 500W should be more than enough. I run two of my servers with 500W PS's and they have nine HDDs each. The higher powered video cards are what use the most energy these days. High end Dual SLI cards can easily use a 700W power supply.

[imdaman]

i see, so i was thinking about a gtx260 with a phenon ii processor and researching from their sites. the video card requires 182W and the highest W for the phenom ii model is 140W so would a 500 W be enough considering the other peripherals on the comp?

[johns0]

I would recommend a good quality brand name psu at 600+ watts if you are going to install a 260gtx,any good psu will have all the connectors you need built in.With a phenom II you will be able to play all the newest games.

[Noahtuck]

i see, so i was thinking about a gtx260 with a phenon ii processor and researching from their sites. the video card requires 182W and the highest W for the phenom ii model is 140W so would a 500 W be enough considering the other peripherals on the comp?

Seriously... did you check those calcs ?

http://educations.newegg.com/tool/psucalc/index.html

Is your CPU going to be a dual core ? Quad core ?

It has what you want to use listed.

But i would go with johns0

A good 600watt PSU is not very expensive.

And i doubt you would ever notice difference in your electric bill between a good 500w or 600w.

Do what i do, turn it off once or twice a week for a night

[imdaman]

sorry noahtuck, didnt give that one a look. what is the considered a high end motherboard? i havent decided on a motherboard to get yet

[slh2080]

I've been told a "single rail" 12V supply is the way to go.

[Moontrash]

i built my pc back in Feb....Phenom 9950....RADEON 4870...4 gb's of Mushkin RAM...etc...thought since i was gonna be getting a big Video Card that the wattage had to be high...i grabbed an OCZ 700 watt power supply...i was told that was a bit of overkill but i thought why not, a few xtra watts wont hurt a thing...i tested my pc with my wattage meter and at max gaming i dont get past 250 watts and at idle i dont go past 183 watts...period...redwudz mentions the 2 video card or SLI for power consumption and he is correct...if your gonna use 2 video cards then 600 is fine but if your just gonna use 1 then 500 will work

[imdaman]

so i just bought the Galaxy GeForce GTX 260+ OC Video Card - 896MB GDDR3, PCI Express 2.0 x16 and the Cooler Master
eXtreme Power Plus 600W ATX Power Supply.

I was reading the min req for the gtx and it says, "500W PCI Express-compliant system power supply with a combined 12V current rating of 36A or more"

I'm not really sure how to read the power settings but I'm guessing the 2 +12V@18A is meets the 36A right?:

Load Range
+3.3V@25A; +5V@30A; +12V1@18A; +12V2@18A; +-V@0.8A; -12V@0.8A; +5VSB@2.5A