eVGA 9600GSO Dual-Slot volt mod?

OrangeGator,
The VID-mod changes vGPU without the VR.

Please see/measure if the pads on which VID4-resistor was mounted on are still connected. Like via a tiny bridge of solder.
That would explain your voltage drop as VID4 makes quite a difference:
1.31250V is VID0: shorted (0), VID1: no connection (1), VID2: no connection (1), VID3: shorted (0), VID4: no connection (1), VID5: shorted (0) and VID6: no connection (1).
And VID for 0.93750V is the same as 1.31250V, but 0.93750V has VID4 shorted (0).

Quote:

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Originally Posted by largon

OrangeGator,
The VID-mod changes vGPU without the VR.

Please see/measure if the pads on which VID4-resistor was mounted on are still connected. Like via a tiny bridge of solder.
That would explain your voltage drop as VID4 makes quite a difference:
1.31250V is VID0: shorted (0), VID1: no connection (1), VID2: no connection (1), VID3: shorted (0), VID4: no connection (1), VID5: shorted (0) and VID6: no connection (1).
And VID for 0.93750V is the same as 1.31250V, but 0.93750V has VID4 shorted (0).

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Hey largon. Are you sure that shorted =0, open =1? It seems like it's the other way around, as quadomatic guessed earlier. But I'm a noob and really don't know. I'm almost certain that the resistors were removed and there was no solder bridge.

Anyway, long story short, I fixed it. I added a 100K vr and have tuned vGPU to 1.31V. Currently stable at 753/1890 and still testing. No problem with overvoltage protection so far. My advice, do Not remove resistors. I have a feeling that the diagram showing which vid resistor is which is incorrect or removing them doesn't have the results we'd expect.

Ok, long story for those interested. After removing the two resistors and getting a vGPU of 1.04, I was able to successfully re-solder vid resistor 4 back and got 1.16V. I then tried to re-solder vid 2 back, and remove vid 3. Well, I removed vid 3, but for the life of me could not get vid 2 back on. Damn things are small and wouldn't stick. In the process, vid 4 came off and would not go back. So, in desperation, I put solder bridges over vid 2 and vid 4, leaving vid 3 open. This resulted in 1.14V. I then picked up a 100K vr today and added the mod. I was then able to tune vGPU to 1.31V from the 1.14 previously.

Copy-paste from RT8802A datasheet referring to the VID tables:

Quote:

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Note: (1) 0 : Connected to GND
(2) 1 : Open

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Good to see more progress has been made!

Unfortunately for me, I don't seem to be getting much of any performance gains out of the 9800GT. I can't get the core, shaders, or memory as high as it was on the 9600GSO either.

not too unusual.. more onboard cache with the extra 16 SP's = more internal heat to be removed, before instability occurs.. Better cooling is in order.

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Originally Posted by CL3P20

not too unusual.. more onboard cache with the extra 16 SP's = more internal heat to be removed, before instability occurs.. Better cooling is in order.

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Actually it's probably not a heat issue. I replaced the reference model cooler with an Accelero S1 and a Twin Turbo module. Temps peak at 55 degrees or so. It's probably voltage related, but I'm not so inclined to do a volt mod anymore :P

Maybe a bios flash. It might not be set to 1.15V.

Quote:

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Originally Posted by quadomatic

Good to see more progress has been made!

Unfortunately for me, I don't seem to be getting much of any performance gains out of the 9800GT. I can't get the core, shaders, or memory as high as it was on the 9600GSO either.

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I'm happy with the final results. My OC went from 660/1674/930 to 756/1836/1080 stable @ 2.0V vMem, 1.32V vGPU. Temps top out at 72C with stock cooler. I tried higher volts, but couldn't get anything higher stable due to temperatures. With better cooling, I'm sure it'd clock even higher. But as it is, I get 12,566 3dmark06 with my e7200 @3.7ghz.