Weird SLI Problem

[IYP]

Well i vmodded my cards last night and i was having a weird problem of the computer just shutting down halfway thru GT3. Ive narowed it down to the cards @ semi-high volts (1,55) and high clocks, it will do that with everything @ stock so i looked for a cause for a problem. It seems that the second card is not enabling 3d voltages right off the start for 3d apps :confused: which seems a little odd to me...havent heard of it before. i must have been setting the second cards 2d volts to 1.55 and when it finaly kicked it it would go to 1.81 and enable OVP and shutdown.

Does anyone know how i can force the switch to 3d volts of a fix for this problem :confused: ?

-thanks

[IYP]

can anyone out there help me out?

Hilf Mir

[EmineM]

well I had the same problem with my SLI system it always crashed during the last test of 3dmark05. Solution was changing my PSU from a OCZ 600W to a Enermax 620W Liberty, if I remember correctly the OCZ has 18A / 20A on its 12V rails and the Enermax has 22A on the rails so maybe that made the difference at least its not crashing anymore :)

[Kasparz]

I flashed selfmodded 7800gt bios@1.5V on 2D and 3D.
Your cards are hardmoded?
Find mooded bios somewhere, or mod it yourself.

[persivore]

Check that you have the same BIOS on both cards. Some BIOS' will set the 3d voltage as soon as drivers are loaded, and others will set it when the card enters 3d mode.

[Elfear]

How are you setting the volts? I just slapped a multimeter on and than measured the volts with ATI Tool running in the background. Just watch for the voltage jump when ATI Tool starts and then dial in the voltage you want. That does seem a little odd that one card doesn't kick up the volts as soon as the other.

I'd also recommend that you set each card individually. I threw one card in at a time and it worked great.

[IYP]

presivore, are there any other coauses to this...i bought the cards in the same order from the same place but i will reflash and see, thanks for the responses

[persivore]

presivore, are there any other coauses to this...i bought the cards in the same order from the same place but i will reflash and see, thanks for the responses
I think the BIOS' might just be set to change voltages at different points, but I'm not sure. I've seen a similar problem on a 6800LE when flashing differnet BIOS' to it as well :confused:

[CHaynes112]

did you find a resolution for this yet?

[gocchin]

I had the exact same problem with my two XFX 512 GTX's, and they are flashed with identical bioses. The card in slot 2 was showing 2D voltages at 1.4v and the card in slot 1 was showing 1.68v but it was showing the 3D voltage even not in 3D apps and idle. So I mistakenly thought the card in Slot 2 had mistakenly turned down the volts so I upped it back to 1.68v...started running 3Dmark and kept blacking out or restarting.... Finally I measured the card 2 in 3D load and it was hitting 1.99v, figures it was shutting down. Slot 2 seems to show the card in 2D while slot 1 shows 3D, weird. I then tuned them both under load to run around 1.7v but was still shutting down... and turned out it was a cold bug with the bios I was running using the GDC adder and my chilled water...

[IYP]

hmmm, there both on air so i doubt there tripping the coldbug....overheating perhaps? could that be causing the 2nd card not to switch into 3d....but wait that would mean it would have to be overheating at idlefor the 2nd card not to switch voltages...which i doubt.

you think the bioses with the GDC adders automaticaly behave like this?

[revenant]

sounds like lack of power... *or* one of them is over-heating and shutting down... just my wild ass guesses.