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My actualpsu can't handle my new gtx 280...

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Grosjambon

Grosjambon

Member
​
Joined
Oct 10, 2009
Location
Montreal - Canada Or @Cegep Maisoneuve
Hi all, I recently boughtr a gtx 280 and i know that my PSU can't handle it.
It is a 500watt PSU 1 x 6pin 1x24 pin and a lot of 4pin/sata thing.
Gtx 280 --- need 1 6pin and 1 6+2pin.
I am on a low budget and i can't put more than 100-150 dollars at max for a PSU to be able to handle the gtx 280
My rig is a Amd Athlon x2 6000+
8gig ddr2 800mhz qimonda
A gtx 280
1Hard Drive 250GB
What do u suggest me buy a another psu or buy a 500watt one with a 8pin connector and just split the power on the 2psu or just buy a 700w + PSU to handle these thing.

Thanks.
 
here is some picture of my computer/psu
DSC01752.jpg
[/IMG]
DSC01753.jpg
[/IMG]


Picure appear big but i dont know how to fix it :)
 
While it's listed as a 500w power supply (whether it is or not is anybodies guess) it only claims 25 amps of 12 volt power, or 300 watts.
A gtx280 is said to use 200-240 watts of power, all of which comes from the 12v supply.
That is 17 to 20 amps right there.
The CPU is also powered off the 12v line, and uses probably 80-90 watts, or 6-7 amps.
Best case, that's a 23 amp load on the 12v line. Add in the hard drive and the ram and you're at 24 amps. Worst case, you're at 27 amps.
Either way, an off-brand power supply claiming 25 amps can rarely actually put out 25 amps, and you're over loaded.

You need a quality brand PSU, look for anything made by corsair or antec(there are other good brands too, just can't remember 'em offhand) that has 40 amps or more on the 12v line (on PSUs with more then one 12v line(rail) make sure you find the combined total, simply having three 15a lines(rails) does not mean it can do 45a, usually there is overlap between the lines), that will power the card and CPU and such happily.
 
Bobnova said:
While it's listed as a 500w power supply (whether it is or not is anybodies guess) it only claims 25 amps of 12 volt power, or 300 watts.
Click to expand...

Wouldn't that be like 400 W? I thought 300 W was only around 15 amps.

Despite your calculations look correct.

Because PSU manufacturers seem to use a different definition. A good 300 W PSU usually has 15 amps on the 12 V rail and a good 400 W PSU 20 amps on the 12 V rail, unless the 5V rail amp rating gets subtracted.

But, that's with the pre-2005 ratios.

Looks like the current ATX revision would call for subtracting the 5 V rail. Thus, don't be surprised if the 5 V rail amp rating is low on today's PSUs.

This PSU looks like it's based on the older ATX specs. (when AMD used the 5V rail for the processor) (when socket A was dominant)
 
Last edited:
You can get a Corsair 550VX for $80 from NewEgg ($60 after $20 MIR) that should be plenty of power for your system.
 
Thanks +_+
Well This PSU Is 4years old and he,s still working :)
So u suggest me a Corsair with more than 40AMP on the 12 Rail it is consider that a powersupply have 12v @ 70A it should be enough for a gtx 280 and all my component. I can buy a 850w corsair for 150Boxe he's 2week old
Link : http://montreal.kijiji.ca/c-acheter...Z-500W-1000W-SLI-CROSSFIRE-W0QQAdIdZ163635514
(the 850w one not the other ) is it a good deal or its better to buy a brand new power supply.
Or this 750w PSU from ncix http://www.ncix.com/products/index.php?sku=26415&promoid=1059 the 750w have 60AMP on the 12V rail.
 
RJARRRPCGP said:
Wouldn't that be like 400 W? I thought 300 W was only around 15 amps.

Despite your calculations look correct.

Because PSU manufacturers seem to use a different definition. A good 300W PSU usually has 15 amps on the 12 V rail and a good 400 W PSU 20 amps on the 12 V rail, unless the 5V rail gets subtracted.
Click to expand...

No. 12V x 25A definitely makes 300W. Not all (if any) PSUs can supply full power on every rail simultaneously. Each rail has a maximum, and then there is a combined maximum, which is usually less than the sum of the maximums of each rail.

12 * 25 = 300
5 * 35 = 175
3.3 * 28 = 92

300 + 175 + 92 = 567 != 500
 
petteyg359 said:
No. 12V x 25A definitely makes 300W.
Click to expand...

Makes sense, but, they don't look all dedicated!

The 300 W rating I saw was just the 5 V and 12 V combined. Appears that the 3.3 V rail shares them!

On a 300 W PSU, the better ones typically have this printed:

3.3V = 28 A

5 V = 30 A

12 V = 15 A
 
Last edited:
Grosjambon said:
Thanks +_+
Well This PSU Is 4years old and he,s still working :)
So u suggest me a Corsair with more than 40AMP on the 12 Rail it is consider that a powersupply have 12v @ 70A it should be enough for a gtx 280 and all my component. I can buy a 850w corsair for 150Boxe he's 2week old
Link : http://montreal.kijiji.ca/c-acheter...Z-500W-1000W-SLI-CROSSFIRE-W0QQAdIdZ163635514
(the 850w one not the other ) is it a good deal or its better to buy a brand new power supply.
Or this 750w PSU from ncix http://www.ncix.com/products/index.php?sku=26415&promoid=1059 the 750w have 60AMP on the 12V rail.
Click to expand...

40A is plenty (12V * 40A = 480W). If you're just running the single card, there's no need for a huge PSU.
 
petteyg359 said:
No. 12V x 25A definitely makes 300W. Not all (if any) PSUs can supply full power on every rail simultaneously. Each rail has a maximum, and then there is a combined maximum, which is usually less than the sum of the maximums of each rail.

12 * 25 = 300
5 * 35 = 175
3.3 * 28 = 92

300 + 175 + 92 = 567 != 500
Click to expand...

This is correct. 15 Amps on the 12 volt rail, would be 180 watts. I don't even think there are quality PSU's made these days with 12 volt rails that small, but I could be wrong. I think even the Corsair 450VX has a 12 volt rail over 30 Amps.
 
The EarthWatts PSU line is an excellent choice as well. I believe (read somewhere, can't remember where, someone may be able to cite a reference) the EA series over 500 watts are Delta built, and if it isn't Delta OEM, it will be Seasonic, which is one of the best OEM's right now.
 
That antec 650 would do you nicely, it has 45 amps of 12v total, which will be plenty.

My corsair 400w has 30a 12v, any other corsair will have more then that :D
 
Grosjambon said:
http://www.amazon.com/Rocketfish-700-Watt-ATX-Power-Supply/dp/B001FHUYPI#moreAboutThisProduct I found that one on Kijii for 65boxe.
It has 2 6pin connector a 8pin connector, they say that the 8pin is for the cpu but can i put 8pin + 6pin on my gtx 280 and the other 6pin in the mobo 8pin connetor idk if ucan plug a 6pin connector on it. I know a 4pin fit and a 8pin does a 6pin can fit?

THanks for replying
Click to expand...

I don't recommend that psu I used to have one and it dies in less than a year and my other system specs where not that high I really don't recommend that Power supply.
 
Bobnova said:
You need a quality brand PSU, look for anything made by corsair or antec(there are other good brands too, just can't remember 'em offhand) that has 40 amps or more on the 12v line (on PSUs with more then one 12v line(rail) make sure you find the combined total, simply having three 15a lines(rails) does not mean it can do 45a, usually there is overlap between the lines), that will power the card and CPU and such happily.
Click to expand...

Lol, Seasonic dude..... They make the best of the Corsair units.

If you do want something thats just cheap, Topower make some passable units but just be aware that they're not even in the same class as the likes of Seasonic/Corsair and Antec
 
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