DONT USE AN ADDITIONAL PSU TO POWER YOUR X800 CARDS!!!

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Originally posted by spaceman
Seems like if you used the secondary PSU for your fans & drives, and left everything else hooked up normally, it should be OK. :confused: I think I'll choose NOT to be the guinea pig for this test tho. :p: ;)

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yes, because the card tries to take the power it has gotten from the secondary PSU, and use the ground through the motherboard from the primary PSU, which results in the prepackaged smoke which is sealed in during the manufacturing process, to be released from the card, rendering it unusable.

shamino told me its actually possible to use a second psu to power x800 cards. i hope he describes how to do it soon :)

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LardArse wrote on 08-22-2004 01:11 AM:
Well its not too difficult just have to connect the green wire of both psus together and then one of each of the black. Thats what I do and my card is still alive but I cannot be so sure or garantee that this works for everyone or card etc.

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has anybody else tried this?

dont u just make sure the psu powering the x800 is also powering the mobo? the other psu can handle everything else (hdd's, cd roms, fans, dancing robots)

edit : just sure his quote, nvm... that sounds difficult :D lol

I was wondering if it's safe to use the new Coolmaster Stacker case which comes with a special Y-shaped dual psu cable which pulls into the board with a X800Xt since they both IMO are grounded to the board??? Or am i wrong???:confused:

well afaik the cards use the agp slot grounding so you need to connect the ground cables of both psus? im not sure, shamino tried it and got it working fine after he killed a card on his first attempt as well, so i guess his trick should work for everybody.

but it might be mobo/psu related and be different for other board and psus, so try it at your own risk!

I killed a card last time when this was done and the card was not slotted in totally on one end. Think it should be fine as long as card is slotted in properly.

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Originally posted by saaya
well afaik the cards use the agp slot grounding so you need to connect the ground cables of both psus? im not sure, shamino tried it and got it working fine after he killed a card on his first attempt as well, so i guess his trick should work for everybody.

but it might be mobo/psu related and be different for other board and psus, so try it at your own risk!

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its card specific, not mobo specific.

so some x800 cards work with 2 psus while others dont? 0_o

i thougt they all used the same pcb?

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Originally posted by ROACH
I was wondering if it's safe to use the new Coolmaster Stacker case which comes with a special Y-shaped dual psu cable which pulls into the board with a X800Xt since they both IMO are grounded to the board??? Or am i wrong???:confused:

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hmmm what does it look like? link?

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Originally posted by saaya
so some x800 cards work with 2 psus while others dont? 0_o

i thougt they all used the same pcb?

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I meant it prolly depends upon the model of card. The motherboard would have nothing to do with whether the video card tried to ground through it or not.

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Originally posted by saaya
has anybody else tried this?

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Yes, I tried that with my primary system (Radeon 9800 AIW connected to the secondary PSU) and no rpoblem for over half a year now. ;) I don't think that it's different for the X800. :D

well if you will read the thread you will see it IS ;)

ive also powered my 9500np@9700pro with an extra psu w/o a problem, but the x800 cards seem to need to be modded to work with an extra psu.

Woa big :banana: :banana: :banana: :banana:!

So the problem isn't from the Antec psu's right?

In the other way, it wouldn'y make any sense that some cards work fine and others don't.

Glad I seen this, I was fixin to do this also & with a Antec. Good go yall, probably saved me some major problems.

I have had my share of stuff dying lately to. To much to even think about.

I would like to see a for shure fix on this. Going to need more power Scotty.

well the trick shamino posted "should" work for all psus and cards, im just not 100% sure and held responsible if anything goes wrong.

so try at your won risk, but as i said, it "should" work.

Using a second PSU is no problem AFAIK. Having the second PSU running while the one connected to the mobo is NOT, however is asking for trouble.

I dit it to my first x800.. had just hooked iy up to tha Vapo, and was planning on doing some FX53 3Ghz x800XT benching. I switched on the second PSU and noticed a fan connected to the Mobo started running. Then i thought i saw some smoke coming from underneat the x800, wich my nose quickly confirmed. I REALLY hate that smell. Its the smell of dissapointment
and an aching wallet.

Is this an X800 only thing or could it affect 6800 also? I'd say a 6800ultra would benefit more from getting power from a second psu as it needs more power.

Here's what is most likely happening:

When you have the graphics card powered off an external psu - as per usual the gfx dual regulators regulate power down for vgpu and vddr (along wit vtt)......now its possible that x800 pro's are regulating their own 3.3v supply - which is normally supplied via the AGP slot.

With the card powered up and inserted into the slot...and the motherboard unpowered, the card could be feeding that 3.3v back down the agp slot - and having to power half the motherboards 3.3v devices along with itself, the heavy load of which is burning out the regulator on the card.

Maybe it isnt the 3.3v supply but another one - its probable though that its one of the cards supplies thats ending up going back down the AGP slot and trying to power other things on the motherboard, or shorting out through a mobo's mosfet (reverse current)

My Abit Nf2 boars died when having a secoundary psu connected to my 9700Pro, but it worked fine as long as i had the primary psu that was connected to my mb running.
Forgot to connect my relay(?). Therefore i think the agp slot or the sb was fried.

To Sayaa: I did it as Lardass wrote the first time i tried it, worked fine (with my 9700Pro). But later on i used a relay connected to 12v wire on a molex so that i only had to cut the green and black wire on the secondary psu (not on the primary).
I think its no problem if one have both psu power up simultaniously. but then again i have no X800.

i think froudeg is probably right and the only problem is powering up the seocnd psu before the first is running.

so the trick is to power both at the same time wich shaminos trick is doing.

You misunderstood my first post. The way to do it without having to cut the wires of your primary PSU is a very simple one. Have a look at the following pic!
It shows the backside of the motherboard ATX-connector:

http://www.techpowerup.com/articles/...itionalPSU.jpg

As you see, you just solder one cable to PS_ON and one to ground, connect the soldered on PS_On-cable to the green cable of the secondary PSU's ATX connector and ground to ground on the secondary PSU.
Both PSUs will start at the same time, without a problem and without frying anything.

BTW, I read the thread ;) :D

what about something like this http://www.coolpc.com.au/catalog/pro...roducts_id=630 ?

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

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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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Yea, thats just connecting the green wire of the atx connector to ground on your other power supply. I imagine lardarse't 'trick' would work, but I'll leave it to someone else to test. :p:

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Originally posted by eva2000
what about something like this http://www.coolpc.com.au/catalog/pro...roducts_id=630 ?

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

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That looks like just the ticket. That way you wouldn't have to go cuttin' wires. :cool: I wonder how hard it would be to find tho, since we don't ALL live in Australia. ;)