Who's Who In Power Supplies, 2011: Brands Vs. Manufacturers

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AakeKaake

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So apparently i.e. SeaSonic is pretty good manufacturer?

For development of this guide: What should high-end pc users consider PSU-wise when processor OC'ing and Crossfire/SLI comes in picture?

Whats good in wattage for SLI GTX 780 Ti or CF R9 290X?
 

nukemaster

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Seasonic is considered to be one of the BEST power supply makers on the market.

This is a comment thread, please create a thread in the actual forums(components section.) for more help.
 
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Nvidia has a pretty good reference guide for this, I'm not sure about AMD.

You should just google "PSU calculator". There's a tool created a while ago that will let you input the devices and/or their wattage for your whole system and then figure it for you. You usually want to overshoot that amount by 20-30% if you intend to add on down the line.

For my system (in my sig), the minimum would be around 700W functional wattage (under load and real output) so a 750 80+ Gold would be required or an 800 80+ Silver. I opted for an 850 because the cost difference was minimal and I wanted some headroom.

The rating is a big factor. If your PSU is only 85% efficient, for example, then your 700W might do 600W under load if you're lucky; if it pulls more you're likely to blow a cap or the transformer down the line.

Do some reading on reviews to see what the real world efficiency is of the PSU first.

Seasonic is always a reliable bet. They often out-perform their 80+ rating.
 

nukemaster

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100% WRONG.

80 + has NOTHING do so without output power. It is all about the INPUT to output ratio. It tells you how much power a unit will waste to make its output(within certain load levels).

When turning AC to DC and dropping the voltage you ALWAYS have some loss. Older linear systems used to get rid of the extra voltage as heat(they acted like a large resistor generating lots of heat. You would first drop the voltage fairly close with a transformer then switch it to DC and filter and regulate it).

When switching came along with the idea of rapidly switching the power on and off(transistors fully on are more efficient than in other mid way/analog states). This made computer power supplies as we know them possible. At a later point they found ways to make them even more efficient(things like dropping to 12 volts and then getting the 5 and 3.3 off that rail[dc-dc converter] saved lots of wasted energy).

At worst an 80 plus bronze power supply will generate more heat and use more power so the designer will have to increase fan speed to keep it within thermal specs.

Do not confuse 80+ with the pile of cheap/older design power supplies that are on the market and not suitable due to lack of protection or much lower 12 volt rail currents. You can get and "old" or old design 450-500 watt power supply with less 12 volt current than a modern 300 watt unit. This is because hardware had made a switch from being 3.3/5 heavy to using 12 for almost everything(higher voltages allow more wattage on smaller wires than lower voltage.).
 

RedJaron

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Yep. Even then you still have a few PSUs made today that advertise high total capacity, but get there with much stronger 3 and 5 volt rails than practical. Checking the sticker reveals the wannabes from the quality products.

And Chris, if you have a recommended PSU calculator, please list it. Most of the ones I've tried grossly overestimate PSU requirements ( mostly to hedge bets when using the aforementioned weak PSUs. ) I've seen some that try to get way too specific ( though fairly accurate, ) and would be rather confusing to many tech-savvy people.
 

nukemaster

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I will take an overestimate over an underestimate any day. At least with too much a user does not have issues.

In general if a price is too cheap, chances are it is an older design that is not suitable for today's systems(my real point was just about 80+ not being how much less a power supply delivers and all about how much more is uses to get to the same place.)

Heck the 300 watt power supply in my media center(i5 750 + gtx 650 ti 1 x 2.5 and 2 x 2.5 inch drives. I have yet to see this system top 180 at the wall.) out powers my older 450 watt power supplies.

That 450 watt power supply was from a time that less hardware used the 12 volt rail(s) and its 450 watts is combined over 12/5/3.3/-12/-5/5vsb while modern power supplies will have 12/-12/5vsb the 5 and 3.3 come off the 12 volt rail meaning you can get a fair bit of 3.3 and 5 if you need it at the cost of some 12(allowing some older hardware to work without issues).

I was not trying to bash Christopher Shaffer, This is just a VERY common misconception(one that needs to end) that 80+ gold means more power than regular 80+. It all comes down to design.
 

ubercake

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Most people don't understand this right away, but it's definitely good to learn.
 

RedJaron

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I wasn't trying to disagree. And yes, I'll take an overestimate as well. But a lot of these calculators will say you need 150W - 200W more than you need. That can be $20 - $40 more than you need to spend for headroom you'll never use. If you're on a tight budget, that money can mean a big difference in other components.
 
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