how to choose a power supply

[ayushh]

I am lost what power supply to use i got these parts .Cant decide what comany should i trust with my power supply

These parts i got around and selected

a 1660 or 1660 ti

gigabyte b450 https://www.amazon.in/GIGABYTE-B450M-DS3H-Ryzen-Motherboard/dp/B07FWVJSHC/ref=sr_1_1?keywords=gigabyte+b450&qid=1569654082&smid=A3V2EW7ECP49IZ&sr=8-1

amd ryzen 2600 

or i will be going with a 

i5 9400f but i dont know what motherboard should i go with or which of these cpu is better than another

a 1tb seagate drive i already have that

8 gb ram 

a wifi adapter 

and i dont know anything else about the case or what atx micro atx means

 

[Bloody-George]

First of all, where do you live? Depending on the country, some PSU deals are better than others. In general, that's a pretty light build. 500ishW power supplies will handle your rig very well, provided they are decent units. 

 

Corsair PSUs are known to be trustworthy, durable and accessible for the regular user. I guess you want to save money and get the best part you can at the same time, so a CX550M would be good for you (semi-modular or modular power supplies are great because you get rid of stressful cable management issues). No secret when choosing a unit for a light build like yours. Go with trusted brands (Seasonic, Corsair, Silverstone...), 80-plus bronze at least, 500W capacity, and you'll be good to go.

ATX means the standard size of most cases/motherboards/PSUs. If a vendor has an unusual form factor, you'll notice it by its nomenclature (micro ATX or mini ITX are the most popular low-profile standards nowadays). 90% of power supplies you find on the market are ATX.

[hello_there_123]

https://www.amazon.in/dp/B01MTZ96RU/?tag=pcp03-21

[PSUGuru]

10 hours ago, Bloody-George said:

Go with trusted brands (Seasonic, Corsair, Silverstone...), 80-plus bronze at least, 500W capacity, and you'll be good to go.

No, that's not how you should choose a power supply. Brand, wattage modularity and efficiency do not indicate quality.

Seasonic: Has the trashy S12II, the Focus+ (Which has bad protections). Their Primes are good, but at their pricepoint, you could get a Corsair HX.
Corsair: As great as Corsair has been doing recently, they do have one PSU that isn't good: The VS series. group regulated and a misconfigured OCP.
Silverstone: No, just no. My research indicated that they fail a lot of performance and quality metrics. I'd avoid them entirely.

As far as efficiency goes, it's not a quality indicator. Efficiency only means efficiency, not quality. And when it comes to efficiency, you're talking between 2-14% on average, which in the grand scheme of things doesn't mean much for money saving.

There's a few good units that are 450w and are great. Corsair CX and bitfenix Formula Gold, for instance.

You should choose a PSU based on:
Is it within spec? 
Is the build quality good?
Does it have a good design?
What protections do they have, do they work and what are they set at?
Does it have a good fan?
After a PSU passes all those metrics, then you can start looking at:
Modularity
Efficiency
Wattage

In response to the thread, hello_there_123 suggested a good one. Corsair CX450 is a solid budget unit with a good design and fully protected. If you plan to upgrade, perhaps get the CX550 so you can have the connections necessary to upgrade the GPU.

[seagate_surfer]

I use a PSU calculator online from outervision:

• https://outervision.com/power-supply-calculator

[hello_there_123]

3 hours ago, seagate_surfer said:

I use a PSU calculator online from outervision:

• https://outervision.com/power-supply-calculator

You're doing it wrong then.

[PSUGuru]

6 hours ago, seagate_surfer said:

I use a PSU calculator online from outervision:

• https://outervision.com/power-supply-calculator

PSU calculators aren't accurate and always overshoot.

The "best" one is the calculator from PCPP. it's more reasonable, but still not entirely accurate. The only way to get accurate wattage is by checking the power consumption of the GPU and CPU. The rest can be a rough 20-40w estimation.