X800 Pro / X800 XT Voltmods?

Glad I could help :)

I suggest you watch the volts realtime under 2k1 Nature, as it seems to push the card really hard (at your highest Vgpu and GPU clock settings). Max I can do in that test without Vgpu dropping like crazy (with 12V@12.2V and 5V@5.8V), is ~1.7Vgpu load (1.73ish idle) and 708MHz. Perhaps I would be better off if I could get the 12V rail lower?

I have a 100k fixed for my OVP and it still drops. Should I use a different resistor? Thanks.

Sik L Cell, no. The OCP mod does not help with the VGPU drop. Only increasing the 5V rail of your PSU probably will.

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Originally Posted by Goldlocke

Sik L Cell, no. The OCP mod does not help with the VGPU drop. Only increasing the 5V rail of your PSU probably will.

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Correct!

Ati loves high 5v rail in generall!

The OVP only "cuts" or "retard" the reset of the power supply of the gpu according to the value of te resistance, 100Kohms is fine!

Still droppin though! 5v at 5.50

Big problem with my OVP mod :(
I have used one fixed resistance from 50k to 37k
Ok,the value originates its passed from 41k to 19.5k..I do not have problems with voltages 1.5v <--->1.85v....Over 1.85v i get shutdowns :upset:
Somebody help me?
Thanks.

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Originally Posted by lsevald

Same problem here. Below 1.6Vgpu I'm getting a 0.03V drop. From 1.6-1.7V the drop is around 0.06V...and closer to 0.10V above 1.8Vgpu. By tweaking the +5 and +12V rails I have been able to reduce the drop to around 0.03V at 1.6-1.7Vgpu. My board seems to like low 12V rail (12.2V is the lowest I can get), and a really high 5V rail (I have mine at 5.8V). The OVP/Igpu mod does nothing for me :( On the positive side my card clocks to ~700MHz on the GPU (room temp water). My current theory is that perhaps I got a GPU that pulls a bit more amps than usual. I have seen this when oc'ing low batch number AMD CPU's (runs hotter, and doesn't like Vcore as much).

I'm also measuring an additional drop of ~0.03V at high loads from the Vgpu caps to the voltage feed pins on the GPU itself:

http://xtremesystems.org/forums/atta...id=19070&stc=1

As for the 0.03-0.06-0.10V drop, I think one of the current sharing channels is dropping out. I haven't been able to understand this fully, but this is what I currently got:

http://xtremesystems.org/forums/atta...id=19071&stc=1

There's two hexfets from +5V->channel2->GND, and two and two in parallell from +12V->channel1->GND. By just considering the number of hexfets pr channel, I think 2/3 of the amps are pulled from the +12V rail and 1/3 from the +5V rail.

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where do I find a guide for those cap mods?