• Happy holidays, folks! Thanks to each and every one of you for being part of the Tom's Hardware community!

How to pick a good power supply?

Toggle sidebar Toggle sidebar
S

Shammikit

Honorable
Nov 30, 2013
174
0
10,690
so im planning to buy a new psu but i dont have a big budget to buy very good psu with these various certifications and i dont even know what most of the mean. i have a budget of $40 and im planning to go visit several shops and buy a new psu by looking at their specs.how can i pick a good reliable one. i did a small research and as far as i understood i should be checking this 12v power rail.how much current should +12V should give out.my current psu gives out 14A in the +12V and 0.5A in the -12V.is this any good
 
Solution
quilciri
Actually, that is a decent unit. I had thought that InWin unit was built by CWT, but it was made by Powerman. CWT makes mediocre PSU's *at best*

However, there are so many things that determine whether a PSU is good or not. Here are few, but I suggest reading a few PSU reviews at jonnyguru to get a better idea

1. Ripple suppression: Actuall current delivered varies widely many times per second, and the PSU needs to minimze it, sending as close to a constant to the res of the PC as possible. The worse a PSU is at this, the shorter a lifespan other components have.

2. performance under load, under heat, and from cold start: some units crap out on efficiency when pushed to near their max load. Some units can't even reach the advertised...
Sort by date Sort by votes
$40 isn't very much for a PSU. What wattage do you need? (400W, 500W, 600W?)

I also don't know very much about PSUs but I think it's important that it is rated "80% efficiency" or above, this generally means that the PSU is of good quality. The cheaper ones will have a "bronze rating" for 80% efficiency.

It really is worth making sure you are getting a quality PSU, if you get a cheap one of bad quality you are risking supplying all your PC's components with bad voltages, which could damage them.
 
Upvote 0 Downvote
Unfortunately there is no way to tell a good PSU from a bad one by looking at the box. You have to read in-depth reviews from websites like Jonnyguru or Hardwaresecrets. 12v amps are important, but so is the construction of the PSU, the capacitors used, the filtering process, the stability of it, and so on. We also need to know what kind of computer this will be powering and the requirements it has.

If you let us know what country you live in and the specs of your system we can help you choose. However for $40 you aren't going to find any decent units. Consider going up to at least $60 for good budget units that will be safe and last many years.
 
Upvote 0 Downvote


i prefer to have something between 400W to 500W as im planning to get a gtx 750ti or a RX 460 2gb
 
Upvote 0 Downvote



Im from Sri Lanka,

my specs:
Motherboard: Asrock G41M-S3
CPU: core 2 quad Q8400 2.6ghz
RAM: 8GB (2*4GB sticks)
GPU: planning to buy a gtx 750ti or a Sapphire RX 460 2GB

 
Upvote 0 Downvote


how can i see if they ship to my country.when i try entering postal code it says invalid pin code.maybe they dont ship to our country
 
Upvote 0 Downvote


No, it is not.

Looks like Barclays has a Sri Lankan presence, but the choices are pretty slim. This is the best PSU I saw there in your budget: http://shop.barclays.lk/bc/itemdesc.asp?ic=14242&eq=&Tp=
 
Upvote 0 Downvote


That's not going to be enough power. You're going to want 550+ especially if you plan on gaming, you want there to be a little extra power within your PSU so that you're not max drawing on power (which can cause unneeded wear). I think something like this ePower 550W would be something up your alley:
http://www.newegg.com/Product/Product.aspx?Item=9SIA2J534N3720

It's on sale until 10/31 for 34.99 I don't know if the sale price would be available to you in Sri Lanka, but you want to make sure when you're getting a PSU it has a good life expectancy, and is something that has good reviews/is from a trusted manufacturer.
 
Upvote 0 Downvote
You do not need that much wattage. The RX 460 draws 100w at peak, the 750ti pulls less than 70w. Your CPU has a 95w tdp, and the rest of your system will pull about 50w. With an rx460, your system tops out at 250w *peak*

Based on this, your system, with an RX 460, will rarely go over 200w.
http://www.techspot.com/review/1221-amd-radeon-rx-460/page8.html

Your system will draw about 18w more than the test system because your cpu draws 4 more watts than the 6700k, and if you're using a HDD, it'll draw about 10-15w more than the bench system's SSD.

I strongly recommend using a quality PSU that may be lower wattage over a cheap, higher wattage unit. You're better off pushing a good PSU at 80-90% capacity than trying to run a gaming system off a cheap unit at all, but you'll only be using about half of the capacity a good 350w PSU, even with the RX 460.
 
Upvote 0 Downvote
In general, if you get a PSU with the rating of the PSU equals the amps on the 12v rail, you should be good to go... 12xamps equals psu watts.
I have an evga 750 platinum...
Go to newegg, and look at the PSU's... you will find that all expensive PSU's tend to follow this.

Getting a cheap PSU, is not a good idea. BUT if you must get one that follows this advice... (evga, sensonic, enermax, corsair to name a few...)

 
Upvote 0 Downvote



isn't the current produced by the 12V rail too low in this?


 
Upvote 0 Downvote


so you telling i should pick the COOLER MASTER Elite RS350-PSARI3-US 350W Power Supply over this IN WIN IP-S450CQ2-0 G (3YR) 450W ATX Power Supply. but isnt this power supply better: http://www.newegg.com/Product/Product.aspx?Item=N82E16817374049 . it gives out more power and more current in 12V rail. how to decide its not good?
 
Upvote 0 Downvote
Actually, that is a decent unit. I had thought that InWin unit was built by CWT, but it was made by Powerman. CWT makes mediocre PSU's *at best*

However, there are so many things that determine whether a PSU is good or not. Here are few, but I suggest reading a few PSU reviews at jonnyguru to get a better idea

1. Ripple suppression: Actuall current delivered varies widely many times per second, and the PSU needs to minimze it, sending as close to a constant to the res of the PC as possible. The worse a PSU is at this, the shorter a lifespan other components have.

2. performance under load, under heat, and from cold start: some units crap out on efficiency when pushed to near their max load. Some units can't even reach the advertised max load at all without dying (some PSU vendors are sleazy and will list the unit according to it's peak voltage rather than it's RMS, thus you could see a 350w PSU from one manufacturer able to actually push more wattage than a "450w" unit from another.) Some units have awful heat dissipation and will drop power instead of overheating, etc.

3. Construction: types of capacitors used, type and number of phases in the voltage regulator, heat dispersion design, soldering, etc. All this translates into how hard the PSU itself has to work to deliver the voltage and in turn, how reliable it is.

4. protection technologies on the PSU (or lacking protections) such as over-current protection (OCP) , over-power protection (OPP), under-voltage protection (UVP), active/passive power factor correction (PFC).

Hope this helps. Cheers!
 
Upvote 0 Downvote
Solution
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom