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Will this psu run an HD 4850?

Last response: in Graphics & Displays
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June 27, 2010 10:20:07 AM

The psu is a lesser known brand, CiT.

It is 550w.

The details on the box are as follows.

+3.3V = 28A
+5V = 30A
+12V1= 16A
+12V2= 16A
-12V = 0.3A
+5VSB= 2.5A

Thanks guys!

More about : psu run 4850

June 27, 2010 10:30:08 AM

hard to tell since most psu's only label the max output not the constant (or average) output.
does it say what the combined 3.3v and 5v are?
it should say something like:
combined 3.3v + 5v output = *** watts
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June 27, 2010 10:32:49 AM

No it doesn't which is annoying.

Only thing it says at the end is "Total Max. Output 550w"

I am trying to search the web to see if i can find it.
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a c 175 U Graphics card
June 27, 2010 10:44:47 AM

A better thing to know is what the total wattage on the 12v1 and 12v2 is. Not much uses the 3.3 and 5v rails anymore.

Officially your supposed to have a 450W (I think) and 30A available on the 12v rail(s). If you have ~360W on the 12v rail(s) you are good to go.
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June 27, 2010 10:53:35 AM

4745454b said:
A better thing to know is what the total wattage on the 12v1 and 12v2 is. Not much uses the 3.3 and 5v rails anymore.

Officially your supposed to have a 450W (I think) and 30A available on the 12v rail(s). If you have ~360W on the 12v rail(s) you are good to go.


if we know what the combined max output for the 3.3v and 5v we can figure out the max output for the 12v (i think)

formula
max output minus 3.3v and 5v output = 12v max output

then

12v max output divided by 12 = amps on 12v rail
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June 27, 2010 11:01:35 AM

Lol i didn't think of just looking on the psu itself.

Ok, here's more annoyance :p .

It shows some more info but not the 12V combined output.

The only combined output it shows is the 3.3V+5V which is 120W MAX.

And then in the row (Peak Output) which is in the same row as the 120W MAX, but still underneath everything else it says 550w.

I didn't word that well lol.
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June 27, 2010 11:10:19 AM

blake1 said:
Lol i didn't think of just looking on the psu itself.

Ok, here's more annoyance :p .

It shows some more info but not the 12V combined output.

The only combined output it shows is the 3.3V+5V which is 120W MAX.

And then in the row (Peak Output) which is in the same row as the 120W MAX, but still underneath everything else it says 550w.

I didn't word that well lol.


hmm....
550 minus 120 = 430
430 / 12 = 36 amps
and if it has 80% efficiency then about 28 amps on 12v minimum ( but these things vary)
WHY ARE PSU's SO HARD TO FIGURE OUT????
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June 27, 2010 11:14:29 AM

alhanelem said:
hmm....
550 minus 120 = 430
430 / 12 = 36 amps
and if it has 80% efficiency then about 28 amps on 12v minimum ( but these things vary)
WHY ARE PSU's SO HARD TO FIGURE OUT????


I doubt it has 80% efficiency since it's a low brand :( 

Doesn't even say efficiency so.
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June 27, 2010 11:21:36 AM

blake1 said:
I doubt it has 80% efficiency since it's a low brand :( 

Doesn't even say efficiency so.


well the requirement is a 450 watt which your one is more, so i think your psu can run a HD 4850
BUT does your psu have a 6 pin power connector?
you need one to plug into the HD 4850 or it wont work
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June 27, 2010 11:26:02 AM

Yeah it does.

I'm just worried if it didn't work or something went wrong, i don't think it has Overvoltage protection so it doesn't fry my pc.

Which is why i am using my other psu because it is better quality but only 405w.
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June 27, 2010 11:38:46 AM

blake1 said:
Yeah it does.

I'm just worried if it didn't work or something went wrong, i don't think it has Overvoltage protection so it doesn't fry my pc.

Which is why i am using my other psu because it is better quality but only 405w.


maybe you should save up some money and get a really good psu and get a HD5770 or 5830
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June 27, 2010 11:57:58 AM

Hmmm yeah i am probably going to get a Corsair CX400w and a 5770.

I have 85 quid atm. I was told the Corsair was great and it could power alot of cards.

And better yet, i can get it for about 34 quid on ebuyer. 5830 is too expensive for me. The 5770 is still high for my price range.

I was thinking about saving enough for the psu, and i can get a 4870 for 85 quid new.

I would prefer a 5770 out of everything but i can't find any good deals.
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Best solution

a c 175 U Graphics card
June 27, 2010 11:58:44 AM

You can use the 3.3 and 5V to figure it out, but its not the best way to do so. If you look at modern PSUs with correct labels on them you'll see that it. Modern PSUs don't load those rails with much anyways, so it should have more power for the 12V rails. All it can really do is paint a worse case scenario.

Quote:
and if it has 80% efficiency then about 28 amps on 12v minimum


It doesn't work like that. Efficiency relates to how much more AC power a PSU needs to take in to generate X amount of DC power. A PSU thats 80% efficient will use 100W of AC power to generate 80W of DC power. If a PSU can make 36A on the 12V rail, then it can make 36A. The efficiency is already built in. If you have a 1kW PSU running at maximum and its 80% efficient then its pulling 1,250W AC from the wall. ((1000 * 100) / 80) A 70% PSU will use 1,429W. See? The less efficient the PSU, the more power it needs to make its rated output.
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June 27, 2010 12:04:56 PM

Best answer selected by blake1.
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June 27, 2010 12:06:50 PM

4745454b said:
You can use the 3.3 and 5V to figure it out, but its not the best way to do so. If you look at modern PSUs with correct labels on them you'll see that it. Modern PSUs don't load those rails with much anyways, so it should have more power for the 12V rails. All it can really do is paint a worse case scenario.

Quote:
and if it has 80% efficiency then about 28 amps on 12v minimum


It doesn't work like that. Efficiency relates to how much more AC power a PSU needs to take in to generate X amount of DC power. A PSU thats 80% efficient will use 100W of AC power to generate 80W of DC power. If a PSU can make 36A on the 12V rail, then it can make 36A. The efficiency is already built in. If you have a 1kW PSU running at maximum and its 80% efficient then its pulling 1,250W AC from the wall. ((1000 * 100) / 80) A 70% PSU will use 1,429W. See? The less efficient the PSU, the more power it needs to make its rated output.


Accidentally clicked best answer, but it's worthy anyway :p 

So, the efficiency is to do with how much power i need to draw from the wall and nothing to do with my amperage? Which is supposedly about 36A? What is your opinion regarding whether it will work or not?
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June 27, 2010 12:13:52 PM

4745454b said:
You can use the 3.3 and 5V to figure it out, but its not the best way to do so. If you look at modern PSUs with correct labels on them you'll see that it. Modern PSUs don't load those rails with much anyways, so it should have more power for the 12V rails. All it can really do is paint a worse case scenario.

Quote:
and if it has 80% efficiency then about 28 amps on 12v minimum


It doesn't work like that. Efficiency relates to how much more AC power a PSU needs to take in to generate X amount of DC power. A PSU thats 80% efficient will use 100W of AC power to generate 80W of DC power. If a PSU can make 36A on the 12V rail, then it can make 36A. The efficiency is already built in. If you have a 1kW PSU running at maximum and its 80% efficient then its pulling 1,250W AC from the wall. ((1000 * 100) / 80) A 70% PSU will use 1,429W. See? The less efficient the PSU, the more power it needs to make its rated output.


LOL
my bad
i just cant get my head around psu's
they drive me nuts
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June 27, 2010 12:34:09 PM

^^^^^^^^^^^^^?????
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a c 175 U Graphics card
June 27, 2010 2:26:12 PM

They can be rather troublesome. The biggest reason why is that the lower end people do their best to confuse the issue. The less people understand about PSUs, the easier it is to sell those 600W PSUs for $20.

Quote:
So, the efficiency is to do with how much power i need to draw from the wall and nothing to do with my amperage?


Is this a trick question? Power = Volts X Amperage. Power is related to how much amperage you have.

A peak 550W PSU depending on quality can sustain anywhere from 500W on down. I'd get you have a real 450W. If you have a max of 130W on the 3.3 and 5V, you have probably around 300W or so on the 12v. (possibly more.) Enough for the 4850, maybe. I'd try it if you think it can. If you haven't bough the 4850 yet, get the 5750. Same power, much lower power needs.
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