Vmodding my 6600

[Cybercat]

The official 6600 vmodding thread is too big, and mostly about the AGP version, which I don't have. I'm looking to do a VCore mod, but don't have any pictures or diagrams for that. I did a VDDR mod, and I'm running at 2.8v now. Is it safe to go to 3.4v?

It's a Leadtek 128MB version if that helps any.

Oh and I'm using RAM sinks. Hot glued to the card, each one lapped, with AS5 underneath them.

[coop]

Have you used that with that cooler? What are your temps at idle? Is it hot glued as well? If that cools as cool as it looks, that's cool.

[Cybercat]

Yes, I've got AS5 on the core as well. No I didn't hot glue it on, I used four screws. It happens to be the stock HSF to my 3000+.

Unfortunately I have no idea what my temps are. This particular 6600 has no temp reader.

[coop]

I recognized the hs, nice work..esp. if you drilled and tapped holes.

[Cybercat]

Yes, I drew a template and drilled the holes into the heatsink.

I'm running my memory at 3.3v right now. Oddly 750-780 has little difference in artifacting. 780 simply freezes though.

[Cybercat]

Perhaps you need some pictures? This is the best I've got:



Could the ISL chip be the VCore regulator? If so, I'm screwed, as it's way too small to solder onto.

[CaTalyst.X]

ISL is definately the vCore regulator. It has 3 regulators so it could be controlling vref and possibly vddq. But I would say a resistor from pin 29 to ground would be the correct mod for vgpu. You shouldnt have to solder to the leg. Just beep test it to SMT components around the IC and you should be able to find an alternate solder point.

-CaT

[Cybercat]

Just beep test it to SMT components around the IC and you should be able to find an alternate solder point.

-CaT

Uhhh, do what now? lol

[CaTalyst.X]

lol check continuity between pins on the IC to surrounding resistors and capacitors.

-CaT

[Cybercat]

ok, looks like I may be able to use a pencil then. but what do I do when I want to find the vsense?

[CaTalyst.X]

you mean the voltage readout point?

-CaT

[Cybercat]

Alright, found the resistor. I'll mark it on a picture soon and post it. So could I theoretically rub over it with a pencil and see what happens? Although I don't have a way of telling what the VCore is running at.

[Cybercat]

you mean the voltage readout point?

-CaT

right.

OK, even though it's really hard to see, I tried marking the place where the resistor is. I also tried to explain where it is.



This resistor, like pin 29 on the regulator, has a resistance of 11.95k.

[Cybercat]

Dammit, penciling is such a pain in the ass. It takes forever to get the particular resistance you want. When we figure out how to check what the VCore is running at, I may just get a 20k VR. So far, I've gotten minor improvements at most. And it's not easy to get a stable setting.

[bh2k]

Wsouolderls Pin 22222452 To Grnd Hahaaahi23u89

[Cybercat]

Wsouolderls Pin 22222452 To Grnd Hahaaahi23u89

Let this be a lesson kids. Don't drink and post.

[Cybercat]

Alright, poking around, I think I've found the VCore measure point.



On my card it measures 1.3v, which makes sense when you consider that the GT version runs at 1.4v default.

Unfortunately the pencil mod doesn't do anything, which makes me wonder if attaching a 20k VR would do anything either. I may buy one though and put it on, if I work up the courage.





.....and the $5 or so needed for the VR of course.