Maximum output I can use from a power supply? - page 2.

crazyates

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Quote from: goxed on October 22, 2012, 10:26:56 PM

Quote from: dunand on October 22, 2012, 12:57:17 PM

I have this power supply : OCZ Z series gold 850w

Can I really use the full 850 watts from the 12 volts continuously or I'm asking for trouble?

What is the maximum power I should use if I want to be on the safe side and lowering the chance of breaking it?

It's 80Plus Gold, it's 88% efficient @ 100% load. So it will dissipate 116Watts at max load. It's almost as much a vanilla 80Plus 650W PSU.
Make sure the PSU is well vented at max load, and use a P3 Killawatt to meter the input load, and never exceed 966Watts.

Really? Yes, a 850W PSU that's 88% efficient will pull 966W from the wall at 100%, but he's asking what % he can run at for 24/7 use. You're not going to run ur PSU at 100% for very long. If you're using a kill-a-watt, try to keep the at-the-wall readings below the rated max, in this case 850W.

muqali

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Like others have said, if you're looking at anything over 750 watts constantly, upgrade. Go 1200W then you don't need to worry for a while. Only time I'd run at 850 is if I had ordered the other stuff and it was on the way.

Unacceptable

legendary

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I personally like to keep a 25% margin or 200 watts.

Seems to work,cause when I don't,it bites me in the butt Embarrassed

goxed

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Quote from: dunand on October 22, 2012, 12:57:17 PM

I have this power supply : OCZ Z series gold 850w

Can I really use the full 850 watts from the 12 volts continuously or I'm asking for trouble?

What is the maximum power I should use if I want to be on the safe side and lowering the chance of breaking it?

It's 80Plus Gold, it's 88% efficient @ 100% load. So it will dissipate 116Watts at max load. It's almost as much a vanilla 80Plus 650W PSU.
Make sure the PSU is well vented at max load, and use a P3 Killawatt to meter the input load, and never exceed 966Watts.

crazyates

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Quote from: ElectricMucus on October 22, 2012, 03:11:06 PM

Power ratings usually come from the available heat dissipation from the switching regulator heatsinks. But that is usually not the problem if the environment stays cool.
The problem are the quality of the built-in fans which are, in almost any case crap.

Ironically if you want to go for reliability it is best to buy a "silent" power supply because those have good fans without you changing the fan and loosing the warranty.
A failure doesn't require the fan to fully fail, just a hickup and under full load the thing will be toast.

That's why I said efficiency is a key factor in determining how high you can run a PSU. The difference in a 1200W PSU between 80% efficient and 90% efficient is > 100W. That's a lot of extra heat inside a PSU. When dealing with a 850W unit (like the OP has) thats 90% efficient (Gold) vs one that's 85% efficient (Bronze), the difference is still 40W. Having the PSU output that extra 50% more heat makes a difference in how much you can run off this 24/7.

ElectricMucus

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Power ratings usually come from the available heat dissipation from the switching regulator heatsinks. But that is usually not the problem if the environment stays cool.
The problem are the quality of the built-in fans which are, in almost any case crap.

Ironically if you want to go for reliability it is best to buy a "silent" power supply because those have good fans without you changing the fan and loosing the warranty.
A failure doesn't require the fan to fully fail, just a hickup and under full load the thing will be toast.

exotime

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I've heard 85% is a safe number for 24/7. Just make sure it stays cooled, or it's going to blow.

crazyates

legendary

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Typically, 80-90% of max is recommended for 24/7 usage. I go by the rule of thumb that you take the PSU's efficiency into account. For an 80Plus PSU that's only 80% efficient, I'd say 80% of it's max load. For your 80Plus Gold, which should be 90% efficient, I'd say you can go to 90% of the max load.

Brand also comes into account, but I think those OCZ ones are good.

dunand

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I have this power supply : OCZ Z series gold 850w

Can I really use the full 850 watts from the 12 volts continuously or I'm asking for trouble?

What is the maximum power I should use if I want to be on the safe side and lowering the chance of breaking it?

Topic: Maximum output I can use from a power supply? - page 2. (Read 1788 times)