Choose a power supply

[Bonhomme Richard]

This is probably the dumbest component in the box. Dumb in that it doesn’t really process anything. It just distributes power to the various components, but it is very important since nothing will work without it. Choosing what wattage you’re shooting for depends on what, how many, and how beefed up the components are in your finished box. My personal preference for a box just to surf and do normal daily activities would be a 300W power supply. Multiple peripherals with moving parts like a hard drive or cd/blue-ray drive usually might warrant a higher wattage if going beyond two of each. The big one is your video card. If you’re getting a massive beast, then I would highly suggest searching some use cases for people with the same card.

Installation is basically just screwing in some screws and plugging in plugs that fit. Not much to it.

 

[Dusty668]

I've got a geforce 9800 GT, currently running at 550 watts, thinking about going SLI which will need another one. Would 850 do it or should I go dual rail and get the full 1000?

 

[Shakey]

Newegg has a PSU wattage calculator: http://educations.newegg.com/tool/psucalc/index.html

Don't skimp on the PSU. The cheap ones won't put out the advertised power, and it may be "dirty". As in the output fluctuates too much. You don't need to go all out and get modular cables and stuff like that, just don't go for the cheapest.

 

[Shegokigo]

Weird, the dream Alienware system I build at their site auto places a 850w PSU with no option for higher.

 

[Bonhomme Richard]

I will admit video cards are a bit of a weakness for me since I spend most of my time writing code and do very little gaming. So, I don't usually spend money on display adapters. But looking at the specs for your card, it's suggesting a minimum 400W for the system for a single card.

That tool looks pretty handy, though I am surprised it gives 850 for Shego. Knowing how much she games and how that would influence a dream system I would have guessed higher.

 

[Shakey]

When you use that it will only show PSU's in that range. I'm guessing it recommended 850 watts, so it will probably only show 800-900 watt ones. If you want more, you'll have to browse to it normally.

---------- Post added at 05:17 PM ---------- Previous post was at 05:11 PM ----------

I did one with 2 GTX 295's and an i5 and it cam out to 1045 watts, not sure what she put in though.

 

[Shegokigo]

I put in double Radeon 5870s.

 

[Shakey]

Maybe they are more efficient, I'm not up on all the new video card specs. Getting a bigger power supply isn't gonna hurt anything, so go higher if you want. This just gives a baseline.

 

[Shegokigo]

Again, it doesn't give an option for higher. I personally like a nice round number like 1000.

 

[SpecialKO]

Make sure you're looking at the maximum wattage, not the peak wattage. "Peak" is the highest it can be cranked up to, but isn't necessarily stable. "Maximum" is how much can be continuously delivered.

Also, check the number and size of the voltage rails.

My GeForece 9600GT requires 2 18A +12V voltage rails for best performance. The 600W PSU I have in there supplies 2 18A+12 voltage rails plus a set of smaller +5V and +3.3V rails for everything else, which come out to a maximum wattage of 648W. So the manufacturer actually rated it lower than it is theoretically capable of, for safety reasons, and so I can game with more than enough power available for everything to run smooth.

Good article on power: http://compreviews.about.com/od/cases/a/PSUWattage.htm

 

[Shakey]

Again, it doesn't give an option for higher. I personally like a nice round number like 1000.

Start here. http://www.newegg.com/Store/SubCategory.aspx?SubCategory=58&name=Power-Supplies

You can then choose 901-1000 or 1001+.

Tekeo, that's exactly why I say don't buy cheap.

 

[Shegokigo]

I was talking about the Alienware site.

 

[Dusty668]

I haven't been able to find a 1000 watt one that won't require rewiring of my apartment, or relocating my PC to the laundry room to use the dryer plug.

I asked one time about rewiring costs, they laughed for 10 clock minutes. Then called the maintenance man in, and did it for 15 more.

 

[Tinwhistler]

you can also tell crap power supplies by the weight.

Power supplies are essentially copper cable wrapped around a core and some capacitors. It's very nearly that low-tech. Which means a heavier psu will likely have heavier gauge cables and bigger capacitors. A light-feeling power supply won't put out the wattage, no matter what the box says.

 

[Shakey]

I was talking about the Alienware site.

Oh. Which computer are you looking at? They seem to like calling them 1KW power supplies instead of 1000 watt. They do have them though.

If you are looking for a new PC, Intel is releasing new processors January 7th so you may want to wait for that.

 

[JONJONAUG]

The power supply is the one part of the computer that absolutely must be of high quality because if it fails it can potentially destroy everything else in the entire system.

Corsair single rail PSUs are the best choice.

 

[figmentPez]

The power supply is the one part of the computer that absolutely must be of high quality because if it fails it can potentially destroy everything else in the entire system.

When I built my first computer I had a stick of RAM, a video card and a hard drive die on me before the power supply died as well. I suspect the PSU killed off the other components, and I'm glad it didn't do more damage. Now I choose my power supplies very carefully.