PC Hardware forum


Is this PSU powerful enough?

by Crusifi6 / November 10, 2012 7:52 PM PST

Hi, I'm new here and didn't know any place to go online for things like this.

Little background, I'm upgrading my GPU to a R7870 which requires a higher PSU. Which means I'm now in the market for a new PSU and was wondering if this would be powerful enough. I know the 7870 needs atleast 500W. Btw I'm 15 and don't have a job. My parents would be buying this for me and it will be a lot easier to break the news if it's cheap since they are already buying me a $200 GPU. It's my Christmas present, so yeah.


The reviews are all over the place thats why im skeptical.

My Specs:
Intel i3-3220
ASRock H77M micro
(soon to be)XFX R7870 (OC version)
8gb DDR3-1600

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All Answers

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PSU selection
by Willy / November 10, 2012 8:25 PM PST

Not all PSUs are the same even with similar wattage rating. That's why you see price differences even though it appears similar. QUALITY matters because this PSU will be the foundation of your PC more than anything you have to count on. So a stable, reliable and good quality PSU is money well spent. On top of that if quality was build-in it will still age over time but do so in a gracious way and remain capable if the components aren't swapped too often. Also, when it comes to PSUs it doesn't hurt if the PC requires at least 500W, that a 650W PSU isn't going to hurt, it will use what it needs. Besides wattage, look for a "single rail design" and 80+ rating. Remember this, cheap is cheap, so pay the price and clean your room to remain on your parents good side.

tada ------Willy Happy

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by Bob__B / November 10, 2012 11:06 PM PST

What your looking for is a 600w or greater.......single rail unit.

Go to Newegg and do a little shopping.
When you find something that you like......plug it into Google.
See if you can find a review........that's where it will show "the good....the bad....the ugly"

Corsair....Pcpower+cooling....make some nice stuff......there are others.

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I second the motion.... and suggest you visit another TECH
by VAPCMD / November 10, 2012 11:41 PM PST

SITE ....http://www.jonyyguru.com

Once you've checked out the WEBSITE, you'll be far better prepared to choose the right PSU for your wishlist.

Look for a PSU that gives you the wattage, the AMPs, the efficiency and the margin of power to allow for additional components or replacement components that take more power for your system.

Once you've narrowed down the choices...then repost here for feedback.


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Opinions on this single 12v rail PSU
by Crusifi6 / November 11, 2012 4:34 AM PST

After a bit of looking i found a single 12v rail PSU with two 6-pins and puts out at least 500W. I read some reviews and they seem to be pretty good plus it's on sale for $30.(40%) What do you guys think? Yay or Nay? I think i might be able to get away with $300 total (including the R7870,) so this is cutting it pretty close to my budget.

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(NT) Care to share a link?
by Bob__B / November 11, 2012 4:58 AM PST
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by Crusifi6 / November 11, 2012 5:02 AM PST
In reply to: Care to share a link?
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by Bob__B / November 11, 2012 5:53 AM PST
In reply to: Link

Well I don't find an independent review for that psu so I'm left to guess.

Could be good........could be junk.

It's not what I would get but it's your machine and your budget.

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Wrong link
by Crusifi6 / November 11, 2012 5:12 AM PST
In reply to: Care to share a link?
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Hmmm....did you look at the buyer ratings for that product ?
by VAPCMD / November 11, 2012 11:16 AM PST
In reply to: Wrong link

It doesn't inspire confidence or provide margin for deterioration or expansion.

Did you look at the expert tech ref provided. If not, you're shortchanging yourself about why all PSUs with the same wattage are not alike and what you should look for in a good PSU. A good PSU should give the rated output in watts on the 12V line alone and 80% efficiency too.

All thinks considered ....I wouldn't put the one you linked in any system I build and I've built a lot
I want to put a system together and never have to open it except to clean it out or add/change components.


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Be aware!
by ZRMaster / November 11, 2012 5:17 AM PST

Hi Crusifi6 !
I sugest you not to buy cheap PSU, you have Intel i3, 7870.... this computer is not cheap... and low end psu can destroy all that... better save money and buy a quality PSU.
I dont say it wont work with cheap one , but in first case of bad input voltage or overvoltage your psu can fail and destroy other components! Very important features that one quality PSU can have:
Over Voltage Protection (OVP), Under Voltage Protection (UVP), Over Power Protection (OPP), Over Temperature Protection (OTP) and Short Circuit Protection (SCP). Also i found info on 7870 chip and it consumes between 250-300W of power when under load and 100 W when idle. (tom's hardware site) so 500W with 80+ bronze certificate (80 % efficient) and single rail 12V - 30 A. i found one for u , take a look :

It costs around 90-95 USD (check yourself, this was on amazon.uk (53 GBP))

Hope this helps!

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or this one
by ZRMaster / November 11, 2012 5:28 AM PST
In reply to: Be aware!
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on newegg
by ZRMaster / November 11, 2012 5:30 AM PST
In reply to: or this one
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Better ...but buyer ratings too low for the price.
by VAPCMD / November 11, 2012 11:33 AM PST
In reply to: on newegg
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Ok guys, I tried to get some knowledge on PSUs.
by Crusifi6 / November 12, 2012 5:15 AM PST

I've spent a fair time reading, trying to learn whats important with PSUs. I've read a lot, and i hope it's paid off.

From my understanding, 80+ certified means the PSU runs more efficient than others. So a 80+ rated, 80% efficiency 500W PSU, would put out 500W at 80% of full power but lose 20% of the 500W when supplying the components. So at 100% capacity the PSU puts out more than 500W to accommodate the loss in wattage, and supplies the computer with 500W. At least that's what I'm understanding from it - Is that right?

Also from reading I came across something that said GPUs don't usually need the majority of wattage that's recommended by the company - that the manufactures try to give you leeway for more power hungry computers? I'm not exactly sure how true that is either. If someone could shed some light on that, it would be appreciated.

Also I tried doing some research on the R7870, and I'm not sure how reliable this graph is but claims it only consumes an average of 145W when gaming.

So could I get away with a good 450W since my computer doesn't need much power as is? I was looking for high rated PSUs and came up with this:



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My lesson was simpler.
by R. Proffitt Forum moderator / November 12, 2012 5:32 AM PST

If I want to have a power supply last a few years I take the total Watts and double it. WHY?

Because Electrolytic Capacitors degrade over time. Push your PSU, add heat and that part wears out faster. It's like your car. Let's put it on the track at 100MPH and how long will it go compared to 75?

Why are you trying to "get away"?

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by Crusifi6 / November 12, 2012 6:19 AM PST
In reply to: My lesson was simpler.

Well my calculations would be that i would only be using 250 - 300W with my set up. And that's at full performance.

Also I'm not trying to get away, I just have a budget since it's not my money. My parents are buying me a R7870 for Christmas so that's why I need a new PSU. And with the R7870 being at $250 i don't have much room to work with. The next low price, well rated 500W+ PSU is in the $100 range.

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Then go for the 500 to 600 size.
by R. Proffitt Forum moderator / November 12, 2012 6:40 AM PST
In reply to: Reply

Not only did you figure out the conversion losses but to go any further to see what we can get away with we have to look at RAILS. Specifically how many and what number of Amperes will be on each rail.

This is another reason I'll double the number and get a single rail PSU. I can pick my PSU out in about a minute this way. I'm sure folk could spend a few weeks on this one.

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by Crusifi6 / November 12, 2012 9:01 PM PST

Like i said the 500W and up are all in the $100 range - out of my budget (not even my money remember.)

Anyways i got some disclosure from http://teksyndicate.com/

Thanks everyone for helping me.

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Get more cash...
by Willy / November 12, 2012 9:21 PM PST
In reply to: -_-

I realize a budget is at stake here. But, take the advise even if you get a 500W PSU that delivers the goods, it may not for long. If you get it all together and it works, wonderfully, it may only for 90 days or less. The reason being as stated in older posts, if you push or rely on cheaper(build) PSU it will fail sooner or later flaunter. AND!!! if it does fail may take something with it, to include anything deemed precious to the PC. Thus, get something that delivers well but also provides a decent measure of "excess" wattage so it remains workable even at probable heavy demanding times. If you game "ALOT", that heat stress is very crippling to any PSU. SO, if you can add any $ to your parents wad, do so. Picking up "aluminum cans" or recycling in general can provide some $. Helping a neighbor do something or ask for small wage, all adds up.

FYI- I strip old PSUs of copper wires and aluminium heatsinks and then junk remainder as ferrous metal with other junk. After awhile i have plenty of junk metal to dump the old p/u and get some $. That at least fills the car with gas.

tada ------Willy Happy

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by R. Proffitt Forum moderator / November 13, 2012 1:22 AM PST
In reply to: -_-
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by Bob__B / November 13, 2012 7:43 AM PST
In reply to: Really?

Are you stirring the pot?

Would you put that 'off the boat' thing in your gaming rig?

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Why yes I have.
by R. Proffitt Forum moderator / November 13, 2012 10:04 AM PST
In reply to: Hmmm.

That and newegg and amazon have supplied a lot of gear for many I know over the years. I wanted to take a quick look at the power supply offerings and for 100 bucks I want a Starbucks card and more.

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