Am a little confused here..

Ati tool is telling me that my xt1900xt-x is drawing 29.1 amps..

All the power supplys i look at has got about 18 to 22 amps max on there 12v rails..

Am i looking at the wrong numbers somewhere???

(Which psu for two xt1900xt in crossfire)

plug em in the mains! just kidding!

i would think a good healthy 30 to 40amps on the 12v line should be plenty enough!

but it has been said many times its the quality of those lines that count. quality PSU's cost more for a reason. and i wouldnt take much notice of Ati tool for voltages!

Overclockers don't do any powersupplys with about 35amps on the 12volt line..

The highest i can find is the
Enermax® Liberty Series Power Supply - ELT620AWT (620 Watt)

+12V1 22A
+12V2 22A

I might be wrong but I think the 12 volt rails are combined.

So 22A on 12V1 and 22A 12V2 would be 44A in total.

dont the OCZ psu's come with 30amps and the tagans are high output supplies also

I am just useing the 430-Watt supply that came as standard with my Antec P150 case, dont know what the amps on it are but it runs my 1900XT-X and my AMD 4400+ X2 plus DVD burner and two hard drives and Sound card without any issues.

Taken from ATI website

Power supply notes:
Connection to the system power supply is required:
450-Watt power supply or greater, 30 Amps on 12 volt rail recommended (assumes fully loaded system)
PCI Express compliant power supply (recommended). Connect directly to the power supply with a 6 pin PCI Express power connector
For CrossFire™: 550 watt power supply or greater, 38 Amps on 12 volt rail

vapor matt said:

dont the OCZ psu's come with 30amps and the tagans are high output supplies also

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Overclockers don't sell OCZ psu..

Tagan 580watt 20amp each rail or combine power of 35amp max...

mmm i thought they did sell OCZ, sorry must have changed then. the tagan's are high output supplies. and what lee87 said in the combined output would be 44amps

lee87 said:

I might be wrong but I think the 12 volt rails are combined.

So 22A on 12V1 and 22A 12V2 would be 44A in total.

Click to expand...

I believe you are correct m8ty

TheMooN said:

I believe you are correct m8ty

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The total current is derated when combined. Should be specified on the psu as total wattage for 12v1+12v2 etc.

chaparral said:

Overclockers don't do any powersupplys with about 35amps on the 12volt line..

The highest i can find is the
Enermax® Liberty Series Power Supply - ELT620AWT (620 Watt)

+12V1 22A
+12V2 22A

Click to expand...

Nah, more like 36A if your lucky.

Look at one of these,

FSP Sparkle FX700-GLN Epsilon 700W ATX2.0 PSU (CA-001-SK)

At least 50A combined 4x12v

Also if you can afford it look for a "PC Power and Cooling" 510 Express. Its so solid its hard to believe the ripply voltage. One of these added 800 points to my 05 score coming from a 480W Tagan.

fornowagain said:

One of these added 800 points to my 05 score coming from a 480W Tagan.

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Did u get a better overclock, or the 800points came from just connecting the psu?

I dont think u need a PSU that overclockers dont even stock. This is the first Ive heard people saying that there is a real issue with even the most powerful power supplies not cutting it. TBH I dont believe it for a second, if it were true, this would be all over the web.

I would say get a enermax liberty 600w but probably over 550w will do. I have a 550w enermax from 3 years ago, it was top of the range then; and there are still only a few powersupplies that has surpassed that wattage.

Dont some cards come with external power supply anyhow?

I agree with above poster that the PC power and cooling are probably the favorite of the extreme overclockers.

Don't be concerned about the wattage. Its meaningless tripe. PSU manufacturers spout all kinds of rubbish. Take a look at what temperature the unit is rated for the measurement, its all a con. Concentrate on RMS values or sustained current supply. And the peak to peak ripple voltage. And I'm telling you a Tagan TG480-U01 didn't have enough juice to run my XTX. Putting a multimeter on the card showed the 12v line dropping to 11.17 volts and the PCP&P makes 12.15 and drops to 12.05.

I thought the card wasn't working as it should, hense the new PSU. Maybe low voltage causes some sort of throttling or clocks not working properly. The OCZ 520 is another to consider as it has adjustable rails and a single 12v rail.

chaparral said:

Overclockers don't sell OCZ psu..

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Doesn't make any difference, he can still get one.

fornowagain said:

And I'm telling you a Tagan TG480-U01 didn't have enough juice to run my XTX. ..and the PCP&P makes 12.15 and drops to 12.05.

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Power wattages can be massaged while being the truth for marketing purposes. This is why u have (in speaker specifications) PMPO (peak modular peak output) vs RMS (root mean square) where el cheapo will use the former statistic.

Id be inclined to stick with good recommended brands with high wattage if ** not about to search out the amp rating on the 12v line of every psu you consider.

One brand to avoid is Q-tec though.

fornowagain said:

Don't be concerned about the wattage. Its meaningless tripe. PSU manufacturers spout all kinds of rubbish. Take a look at what temperature the unit is rated for the measurement, its all a con. Concentrate on RMS values or sustained current supply. And the peak to peak ripple voltage. And I'm telling you a Tagan TG480-U01 didn't have enough juice to run my XTX. Putting a multimeter on the card showed the 12v line dropping to 11.17 volts and the PCP&P makes 12.15 and drops to 12.05.

Click to expand...

My Tagan is powering my X1900 XT @ 690/800 and a X2 4400 @ 2.6 No problem at all. We use Tagan Supplies in our PC which run 24/7 and have only ever had 1 failure and that was a DOA. Really nice quiet supplies.

The Asgard said:

My Tagan is powering my X1900 XT @ 690/800 and a X2 4400 @ 2.6 No problem at all. We use Tagan Supplies in our PC which run 24/7 and have only ever had 1 failure and that was a DOA. Really nice quiet supplies.

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Of the three Tagan's I've owned two have failed on me. This last one was a replacement direct from Tagan. I've always liked them myself, but voltages don't lie. Maybe it was just a bad one, but a 12v 7.5% variation under load is out of spec.

fornowagain said:

Of the three Tagan's I've owned two have failed on me. This last one was a replacement direct from Tagan. I've always liked them myself, but voltages don't lie. Maybe it was just a bad one, but a 12v 7.5% variation under load is out of spec.

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Probably used about 300 supplies by now and like I said we have had 1 DAO failure.