how do i know which power supply i need for a prebuilt computer

[LechTips]

http://www.newegg.com/Product/Product.aspx?Item=N82E16883229564

newegg is really vague
and cyberpowerpc likes to cut corners on the power supply
so if the power supply dies im going to have to buy a new power supply

 

[Eduello]

That CPU is in the lower end of the spectrum, and that GPU is really low end; Even 250W would be easily enough for that system.
Here's a useful list: http://www.tomshardware.co.uk/answers/id-1804779/power-supply-unit-tier-list.html

 

[Guest]

http://www.newegg.com/Product/Product.aspx?Item=N82E16883229564

newegg is really vague
and cyberpowerpc likes to cut corners on the power supply
so if the power supply dies im going to have to buy a new power supply

That's a remarkably poo system, even for pre-built.
I wouldn't give it a chance to die in the first place too, the death of a bad supply can often kill other stuff in the PC.

Anyway, simple answer is, the more you spend the more you get. You don't need to spend a huge amount of money for a decent supply, generally the sweet spot is around 60-80£.
With that said, if you can afford more, it pays off. Higher quality power supplies are not only built far better, so they last a lot longer, but they offer many other features because of that too:

- Fully modular power supplies will cut down on unnecessary cable clutter.

- High quality PSUs will be more efficient, less wasted electricity and less heat. They will have much cleaner signal noise, which in turn helps out your components in the long run.

- Because of the efficiency, most of them will also have fan less modes, or just be completely fan less to begin with.
The more you spend the more headroom you get in regards to wattage rating too.

- All blacked out cables will also be a feature on most high end PSUs.

I would suggest finding a PSU from the manufacturer SeaSonic, widely regarded as the best in the industry. Quite a few brands will use them as an OEM, although it can often be hard to find that in the product details (Not sure why they don't boast it tbh).

Oh and, give building a PC a go. It's quite simple and quite fun when you get into it. You'll also save money by not having to pay for the markup on these things and gain extended warranty periods depending on the components.


Props to the marketing guy that wrote most of the info on that page. I especially liked the description of the R7 230. Hilarious.