2x650W = 1300W psu for X1800/X1900CF/SLI ?

For folks with dual core/sli or cf rigs, how you doing that with 7800gtx sli and x1800xt cf ?

I'm thinking of using this

http://www.coolpc.com.au/catalog/images/2097807533.jpg

http://www.coolpc.com.au/catalog/pro...roducts_id=630

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This adapter cable allows you to run a secondary ATX Power Supply without the need for a second ATX plug on the motherboard. The main power supply simply plugs into the molex connector on the adapter cable, which then supplies the On/Off signal to the secondary ATX PSU via a female 20-pin ATX Cable.

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similar one for non-Aussies http://www.performance-pcs.com/catal...oducts_id=3163

with 2x 650W Silverstone SLI psu http://www.silverstonetek.com/products-65zf.htm

i read there might be dangers with ATI cards doing this but not 7800GTXs ? do X1800XT/X1900XT/XTX ATI cards have any issues ?

how have you got them connected up ? both cards on 2nd psu or 1 video card on main psu and other video card on other psu ? drives and fans off main or 2nd psu ?

looking to add more grunt as i have 2x 650W Silverstone SLI psus here lying around... and 1KW PC Powercooling just landed in Aussie store but too expensive at AUD$795 = US$597 vs 650W Silverstone SLI at AUD$185/each

I have FX-57 0516WPMW and dual core opteron 170 waiting for phase change unit to be completed so thought i'd plan ahead

Motherboards plan to use

DFI NF4 UT SLI-DR
DFI NF4 Ultra-D
Abit AT8 Crossfire

thanks :)

George

That's an amazing tool... I was wondering about that issue cause I want to hook up another PSU too whe I switch to watercooling...

NC™

If you use this just to power your graphic cards, as an example, are the molex's on the cards (12v's) in common with of the 12v's, or grounds on the motherboard (via the pci-e slot)?

If things are in common, you might get some funky things going on if the each power supply has different voltages on it's rails, and they might also vary more under loads, ect.

of course this is just a thought, since i have no clue, and am not sure what is in common between MB and other components (video cards). Just stuff to think about.

yeah i'm really unsure as i just found the ATI thread i was looking for http://www.xtremesystems.org/forums/...ad.php?t=41220

Heh, after reading that thread i wish you luck. All that little connector does is only turn on the secondary power supply if the first psu is on (like a remote turn-on for a car stereo - for the amplifiers). Too bad you can't get schematics of motherboards and videocards, for some piece_of_mind!

I should have a second PCP&C 510 coming to me soon so I'll be running 2x510 = 1020W...I'll be sure to let you know how it goes....

some very interesting things could be happening with these as they are not electrically isolated which means you could potentially create faults and such... not too sure as im only a sophomore of studying crap like this..but depending on the ground and how they are looped this could be ugly..

however from the simpleness of it. i'd say it is just a jumper wire with 2 molex's on it.

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Originally Posted by bullet2urbrain

however from the simpleness of it. i'd say it is just a jumper wire with 2 molex's on it.

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I think the the connector just uses the 12V or 5V of the 1st PSU (one connected to mainboard) to power a relay, which connects the green wire (power on?? i forget the exact name) to ground - which turns on the 2nd psu via the atx connector of the harness. At least is what i get out of the picture and description.

I use an OCZ 520 system and an OCZ 420 for the GT's and zalman coolers. I glued the jump start wire in the molex and I'm good 24/7.

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Originally Posted by afireinside

I use an OCZ 520 system and an OCZ 420 for the GT's and zalman coolers. I glued the jump start wire in the molex and I'm good 24/7.

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Really? Wow, I had always thought it was bad to run two PSU's together unless one is just powering fans hard drives and other components not intertwined with the mmotherboard voltage supply.

I remember this back in the 9800pro days when some guy fried his card since it was running off a different PSU than the Mobo.

i did it for a while... but you have to make sure they are electrically isolated...

if they share a ground or they come in contact.. bad things will/can happen.

fans/watercooling/optical drives are no biggie.

Useless to drop money on those, ALOT easier to merely hard wire them.

Just connect the Green (power on) wire and a ground to Both PSU's and they'll boot togther. Been using that method since I bought my Full-Tower and I never plan on going back. :D

Ah, What the hell, I got bored and pulled out the camera. :cool:

(Be back in a moment, Going to take a picture or two.)

just put the jumper wire in yourself.

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Originally Posted by ShawnMcGrail

Useless to drop money on those, ALOT easier to merely hard wire them.

Just connect the Green (power on) wire and a ground to Both PSU's and they'll boot togther. Been using that method since I bought my Full-Tower and I never plan on going back. :D

Ah, What the hell, I got bored and pulled out the camera. :cool:

(Be back in a moment, Going to take a picture or two.)

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I have the diagram of this from years back, from OCUK or OC.com or something I think..

subscribed. Someone should shoot ATI a e-mail about this.

hey George
i have that exact item, and yes its bought from coolpc...

very handy for dual psu setup, the only question maybe sometimes the second psu wont power off....

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Originally Posted by Victorshen

hey George
i have that exact item, and yes its bought from coolpc...

very handy for dual psu setup, the only question maybe sometimes the second psu wont power off....

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thank guys for the feedback..

Victorshen, that could be a problem if you read http://www.xtremesystems.org/forums/...ad.php?t=41220 but that's for a different ATI model of card... so confused as always heh

I still maintain that a pcp&c 510 SLI will run anything out now and in the next year at least most likely 2

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Originally Posted by eva2000

thank guys for the feedback..

Victorshen, that could be a problem if you read http://www.xtremesystems.org/forums/...ad.php?t=41220 but that's for a different ATI model of card... so confused as always heh

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i thought it would be wise to have a DMM to measure the output volt first and keep one psu to power up the mobo + vga and the other to handle hdd+fans.....

coz i really dunno what will happen if different volts (say 11.8v & 12.2v) are applied to mobo and vga cards....

I have the CM stacker and it comes with a connector similar to the one pictured above. I have not used it as I have not had power issues yet.

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Originally Posted by J-Mag

Really? Wow, I had always thought it was bad to run two PSU's together unless one is just powering fans hard drives and other components not intertwined with the mmotherboard voltage supply.

I remember this back in the 9800pro days when some guy fried his card since it was running off a different PSU than the Mobo.

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7800s and x1800/x1900 I think regulate their own power. Works fine. 9800s and x800s didn't.

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I still maintain that a pcp&c 510 SLI will run anything out now and in the next year at least most likely 2

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Of course it will. I can run SLI + dual core on an OCZ 420. When you bring balls to the wall overclocking into play, you need all the power you can get.

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Originally Posted by computerpro3

I still maintain that a pcp&c 510 SLI will run anything out now and in the next year at least most likely 2

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Running and performing are two totally different things ;)

One thing I know works with the DFI boards is plugging one supply in to the ATX and 8pin connector. That supply will power the board and all other components (minus the SLId vid cards). Then plug another psu into the floppy connector near the PCI-E slot. This supply will power the video cards only. When the board powers up off the main supply, the secondary fires up as well since it is plugged into the 4 pin floppy connector onboard. So, the secondary is providing current for the SLI action as well as being plugged into the cards.

Not a perfect solution, but a solution untill hard-wiring is figured out.

I feel like I am starting to get close to maxing out my 510 SLi w/ OC this FX60 and all the other crap on my system. I'm thinking PCP&C 800 or 1000. Do you guys think the 1000 is overkill?

Here's a wattage calculator I found:http://www.extreme.outervision.com/index.jsp

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Originally Posted by Hell-Fire

One thing I know works with the DFI boards is plugging one supply in to the ATX and 8pin connector. That supply will power the board and all other components (minus the SLId vid cards). Then plug another psu into the floppy connector near the PCI-E slot. This supply will power the video cards only. When the board powers up off the main supply, the secondary fires up as well since it is plugged into the 4 pin floppy connector onboard. So, the secondary is providing current for the SLI action as well as being plugged into the cards.

Not a perfect solution, but a solution untill hard-wiring is figured out.

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Wouldn't that be bad for the board? With two different rails on it? One @ 12.2v and one at 12.8v for example with 2 different PSUs?