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Resolved Question

Asking the experts

Nov 25, 2011 11:27PM PST

For the past 4-6 months I've been using this power supply:

Discussion is locked

Mrmob11v2 has chosen the best answer to their question. View answer

Best Answer

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What you want to do
Nov 25, 2011 11:48PM PST

What you want to do, is check ALL the specs for that video card. Some of them require a lot more current (amperage) than a PSU might be able to deliver, and then it will trigger that over-current circuit which will shut the entire PSU down, your computer with it.

So find out how much voltage and amperage that video card needs, and on which rails, and then compare it against what your PSU can deliver. It's not just about the raw wattage anymore. If your PSU isn't going to be up to the task, or you're cutting things pretty close, I'd err on the side of caution and get a new PSU that will be able to handle the video card in stride.

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Ok
Nov 26, 2011 12:24AM PST

I can't seem to find the specs of the radeon hd 6770 form sapphire, or just the radoen hd 6770 in general. So I can not find how much power it requires.

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Psu
Nov 26, 2011 1:39AM PST

Your psu has enough total power to run the machine.
The problem is the 12v rails are split.
What that means is you might have to do load balancing to not over load a rail.
Which is why I use a single rail psu and get away from that nonsense.

The 6770 is a 110w card.
Factoring in other parts and applying a fudge factor this psu should work fine.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139027

Your call if you want to spend the bucks.

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thanks
Nov 26, 2011 3:29AM PST

I will only spend money on the psu you sent me if needed thanks for the advice.

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That should be fine
Nov 26, 2011 3:49AM PST

That should be fine. It's unlikely that any vendor will go too far astray of the OEM specs from AMD.

And if they work as they're intended to, those cutout circuits will prevent any damage from making its way to the rest of your system, but there's always some margin of error on these things. Imperfect materials, imperfect construction process, imperfect end result. I wouldn't rely on those any more than you have to. Think of it like the airbags in your car. If you get into an accident, they will likely save your life, but wouldn't you rather avoid the accident in the first place?

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hmm
Nov 26, 2011 6:09AM PST

Well this topic has been by far the most interesting since i set out to build this pc. I would hope this psu would not harm any of my parts but there is no way to be sure and all of the information you have told me has really helped, thanks a lot!

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They don't exist
Nov 26, 2011 8:05AM PST

They don't exist. You get a big enough surge coming down the line, it'll overwhelm any safeguards that might be in the PSU. So your best bet would probably be to invest in a nice high quality UPS. Which will not only take the brunt of any massive surge that may come your way, but also condition the power feed going to the computer so it's a nice steady sine wave like the PSU wants. Not full of little dips and spikes like straight from the AC. So, look for a good UPS with AVR (Automatic Voltage Regulation). If you have the money, an APC SmartUPS might be in order, but there are also some good ones in their lower end BackUPS. And APC isn't the only company to make UPS units. Just don't consider anything that doesn't have AVR (or something to the same effect) advertised on the box.

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what?
Nov 26, 2011 8:26AM PST

What's a UPS ? I am on a budget also like under 70$ so i doubt i'd be able to afford a 300$ UPS, I know there will always be a chance of losing parts in a pc I just want to minimize the risk without going totally bankrupt.

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oops :O
Nov 26, 2011 8:53AM PST

I did some research and found out what a UPS is, making what i said sound stupid.

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No
Nov 26, 2011 9:54AM PST

No. Surge protectors, like those found in power strips, are useless for protecting a computer. If you don't have the money for a UPS now, set aside what you can, and then add a little to it whenever you can until you can afford a decent one.

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thanks
Nov 26, 2011 11:47PM PST

I would still like to add a new power supply with my graphics card for now, just to be as safe as I can. I will go ahead and look for a good UPS down the road so thanks.

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Here's what I have
Nov 27, 2011 1:02AM PST

Here's what I have, though it's far from the only option out there.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371044

Personally, I'd say it's worth spending a little extra on an 80+ PSU. It's largely a marketing thing, but it does guarantee a certain level of efficiency out of your PSU at fairly common load levels of 20, 50, and 100%. Namely that the PSU is at least 80% efficient at those loads, or that 80% of the power the PSU takes in goes to actually powering your computer, not wasted in the form of heat.

While it doesn't guarantee that the PSU is 80% efficient at any other levels, it would be pretty difficult to engineer a PSU that is at least that efficient at some levels and not others. At least based on my rather limited EE knowledge. So, it's not a guarantee, but it does strongly suggest that your PSU will be more efficient overall, and that can have a nice added bonus on your utility bill.

Also, when looking for a PSU, don't just go overboard and get like a 1.2KW (1200W) PSU, because then you're still drawing in huge amounts of power from the power grid that is really just going to be wasted. Unless you're planning on running two of these cards, your current PSU may well be fine. If you really want to get a new PSU too, it's probably worth a little extra to get an 80+ model, but I wouldn't really go above about 650W, or you're just going to end up wasting a lot of energy that you then have to pay for in the form of utilities every month.

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great!
Nov 27, 2011 1:30AM PST

Thanks for the recommendation I really appreciate all of the help you have given me! My main goal with this thread was to find a way to keep my pc at a decent level of safety and I have learned a lot.

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Yup....what Jimmy said
Nov 26, 2011 11:39PM PST

As for the psu.
The "over this/over that" protection is a safety circuit.
In theory if you trip one of these circuits the psu will "gracefully" shutdown.
Sometimes theory and reality don't match.

My answer to this is to install a quality psu and size it to stay well away from these trip points.
That's not a guarantee it just plugs a hole.
I'm not interested in testing how well the safety circuits work......that can get expensive.

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Answer
About balancing the rails.
Nov 26, 2011 3:38AM PST